Module 3 of 47Lesson 1 of 2 · Formulas & Calculator — Whole-Course Summary (SL)
IB DP AI · SL · Prof. Kitso

Formulas & Calculator — your whole course on one page

Every formula you will use in Mathematics: Applications & Interpretation SL, topic by topic — with what to press on the TI-Nspire CX II and what the screen shows.

The calculator is allowed on every AI paper — speed on the TI-Nspire is worth marks.

🗺️ How your course fits together

🚪
Start Herehow the course works
🧮
GDC BootcampTI-Nspire basics
📌
Formulas & calculatorthis page — the whole course
🪜
Learn unitsstep-by-step lessons
🔁
Topic Revision78 subtopics · 879 questions
📝
Mock Sets 1–5full papers + mark schemes

📝 Your exam (SL)

Paper 190 min · short questions🔢 GDC
Paper 290 min · long questions🔢 GDC

🧭 The five topics at a glance — tap one to open it

📖 In the booklet you are given it — learn WHERE it is.
🧠 Learn by heart NOT in the booklet — you must remember it.
[menu] a key to press   Statistics a menu item to choose
⚙️ Before every paper: set up your TI-Nspire (tap)
  1. Turn on Press-to-Test when the invigilator tells you (hold [esc] + [on] from OFF).
  2. [doc] → Settings → Document Settings: Angle Degree for triangles & bearings, Radian for calculus & circular functions.
  3. Display Digits Float 6 (default) — then round to 3 s.f. unless told otherwise.
  4. Store long answers: [ctrl][var] (sto→) so you never retype a rounded number.
  5. The TI shows whole numbers with a dot: 10. means 10.
  6. New page for each question: [ctrl][doc] → Add Calculator.
Topic 1 🔢 Number & algebra12 cards
AI 1.1Standard form🧠 Learn by heart
🧮 On your TI-Nspire CX II
type 3.2›[EE]💻 click EE on keypad›type 5
1.1*DocRAD3.2E5·4E-31280.6.02E233E82.00667E15
💡 The calculator shows 2.00667E15 — you must write 2.01 × 10¹⁵, never ‘E’.
AI 1.2Arithmetic sequence — nth term📖 In the booklet
🧮 On your TI-Nspire CX II
Calculator page›type the formula with n replaced
1.1*DocRAD5+(20−1)·362.
💡 Find n? Use nSolve or a table — see ‘Solving equations’ below.
AI 1.2Arithmetic series — sum of n terms📖 In the booklet
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›4: Calculus›3: Sum (Σ)
⌨️ Type: sum(seq(u₁+(n−1)·d, n, 1, N))
1.1*DocRADsum(seq(5+(n−1)·3,n,1,20))670.
AI 1.3Geometric sequence — nth term📖 In the booklet
🧮 On your TI-Nspire CX II
1.1*DocRAD3·210−11536.
AI 1.3Geometric series — sum of n terms📖 In the booklet
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›4: Calculus›3: Sum (Σ)
⌨️ Type: sum(seq(u₁·r^(n−1), n, 1, N))
1.1*DocRADsumseq3·2n−1,n,1,103069.
AI 1.4Compound interest📖 In the booklet
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›8: Finance›1: Finance Solver…
1.1*DocRADtvmFV(120,6,-5000,0,12,12)9096.98
💡 Money you pay in is negative (PV = −5000). N = total number of periods = k × n.
AI 1.4Depreciation🧠 Learn by heart
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›8: Finance›1: Finance Solver…›I(%) negative
1.1*DocRAD20000·(1−0.15)58874.11
AI 1.5Exponents ⇄ logarithms📖 In the booklet
🧮 On your TI-Nspire CX II
[ctrl]💻 Ctrl›[10ˣ]💻 type 10^›→ log template›type base and number
⌨️ Type: log(b, a) · ln(x) is [ctrl][eˣ]
1.1*DocRADlog3(81)4.ln(20)2.99573
AI 1.6Percentage error📖 In the booklet
🧮 On your TI-Nspire CX II
type abs( or use the |□| template from the [⊞] key
1.1*DocRAD52−5050·1004.
💡 vₐ = approximate value, vₑ = exact value. Always divide by the EXACT value.
AI 1.6Upper & lower bounds🧠 Learn by heart
🧮 On your TI-Nspire CX II
1.1*DocRAD12.5·8.5106.25
💡 Max of a quotient = . Write bounds with ≤ and <.
AI 1.7Loans & annuities (amortization)🧠 Learn by heart
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›8: Finance›1: Finance Solver…›cursor on Pmt›[enter]💻 Enter
1.1*DocRADtvmPmt(240,9,150000,0,12,12)-1349.59
💡 The minus sign on Pmt means money going OUT of your pocket. Total interest = N × |Pmt| − PV.
AI 1.8Solving equations with technology🧠 Learn by heart
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›3: Algebra›2: Solve System of Linear Equations… / 3: Polynomial Tools›Find Roots of Polynomial
⌨️ Type: polyRoots({2, −3, −5})
1.1*DocRADpolyRoots({2,-3,-5})-1,52simult1112-1112-1,6321.2.3.
💡 The wizard asks for the number of equations / degree first. Write the answer as x = …, not just the list.
Topic 2 📈 Functions7 cards
AI 2.1Gradient of a line📖 In the booklet
🧮 On your TI-Nspire CX II
1.1*DocRAD12−35−23.
AI 2.1Equations of a straight line📖 In the booklet
💡 Perpendicular lines: m₁ × m₂ = −1 (learn this).
AI 2.2Composite & inverse functions🧠 Learn by heart
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›1: Actions›1: Define›f(x):=… g(x):=…
📍 Where to find it on the TI-Nspire
⌨️ store a value: type := (colon, then equals) on the keyboard
1.1*DocRADDefinef(x)=2·x+1DoneDefineg(x)=x2Donef(g(3))19
💡 The graph of f⁻¹ is the reflection of f in y = x. Domain of f⁻¹ = range of f.
AI 2.4Graph features with technology🧠 Learn by heart
🧮 On your TI-Nspire CX II
Graphs page›type f1(x)›[menu]💻 click menu on keypad›6: Analyze Graph›1: Zero / 2: Minimum / 3: Maximum / 4: Intersection
1.1*DocRADnSolvex2−2·x−3=0,x|x>03.polyRootsx2−2·x−3,x{-1,3}
💡 Drag the lower bound then upper bound round each root. Do one point at a time.
AI 2.5Quadratic: vertex & axis of symmetry📖 In the booklet
🧮 On your TI-Nspire CX II
Graphs page›[menu]💻 click menu on keypad›6: Analyze Graph›2: Minimum / 3: Maximum
1.1*DocRAD-(-8)2·22.
AI 2.5Rational function asymptotes🧠 Learn by heart
🧮 On your TI-Nspire CX II
Graphs page›[menu]💻 click menu on keypad›6: Analyze Graph›check with Trace
💡 AI SL uses only y = type inverse variation; AA SL needs the full .
AI 2.6Regression models (fit a function to data)🧠 Learn by heart
🧮 On your TI-Nspire CX II
Lists & Spreadsheet›x in A, y in B›[menu]💻 click menu on keypad›4: Statistics›1: Stat Calculations›…Regression
1.1*DocRADExpReg{0,1,2,3},{2,6,18,54},1Donestat.a2.stat.b3.
💡 AI SL models: linear, quadratic, exponential, direct/inverse variation, cubic, sinusoidal. Fitting non-linear regression models with R² is AI HL 4.13.
Topic 3 📐 Geometry & trigonometry8 cards
AI 3.1Distance & midpoint (3D)📖 In the booklet
🧮 On your TI-Nspire CX II
1.1*DocRAD(4−1)2+(6−2)2+(12−0)213.
AI 3.1Volume & surface area of solids📖 In the booklet
🧮 On your TI-Nspire CX II
1.1*DocRAD13·π·32·437.699143·π·53523.599
💡 l is the SLANT height. Cylinder & prism are in the ‘prior learning’ page.
AI 3.2Sine rule📖 In the booklet
🧮 On your TI-Nspire CX II
[doc]💻 File menu›Settings›Angle: Degree›[ctrl][sin] = sin⁻¹
1.1*DocDEG10·sin(40°)sin(65°)7.09238sin-18·sin(30°)641.8103
💡 Ambiguous case: if sin B gives B, the other answer is 180° − B. Check both.
AI 3.2Cosine rule📖 In the booklet
🧮 On your TI-Nspire CX II
1.1*DocDEG72+92−2·7·9·cos(40°)5.78605cos-152+62−722·5·678.463
AI 3.2Area of a triangle📖 In the booklet
🧮 On your TI-Nspire CX II
1.1*DocDEG0.5·7·9·sin(40°)20.2478
AI 3.2Right-angled triangles🧠 Learn by heart
🧮 On your TI-Nspire CX II
1.1*DocDEGtan-151222.6199
AI 3.4Arc length & sector area (degrees)📖 In the booklet
🧮 On your TI-Nspire CX II
1.1*DocRAD72360·2·π·1012.5664
AI 3.5Perpendicular bisectors & Voronoi diagrams🧠 Learn by heart
💡 Voronoi edges are perpendicular bisectors between neighbouring sites. Toxic-waste-dump problems: the best point is a vertex.
Topic 4 📊 Statistics & probability10 cards
AI 4.3Mean, quartiles, standard deviation📖 In the booklet
🧮 On your TI-Nspire CX II
Lists & Spreadsheet›data in A (freq in B)›[menu]💻 click menu on keypad›4: Statistics›1: Stat Calculations›1: One-Variable Statistics…
⌨️ Type: OneVar {2,4,4,5,7,9}
1.1*DocRADOneVar{2,4,4,5,7,9},1Donestat.x̄5.16667stat.σx2.26691stat.MedianX4.5stat.Q₁X4.stat.Q₃X7.
💡 Outlier: more than 1.5 × IQR below Q₁ or above Q₃. σx = population SD, sx = sample SD.
AI 4.4Correlation & regression line (y on x)🧠 Learn by heart
🧮 On your TI-Nspire CX II
Lists & Spreadsheet›[menu]💻 click menu on keypad›4: Statistics›1: Stat Calculations›3: Linear Regression (mx+b)… (mx+b)
1.1*DocRADLinRegMx{1,2,3,4,5},{2,4,5,4,5},1Donestat.m0.6stat.b2.2stat.r0.774597
💡 Only predict y from x inside the data range (interpolation). r tells strength, NOT cause.
AI 4.5Basic probability📖 In the booklet
AI 4.6Combined & conditional events📖 In the booklet
💡 Mutually exclusive: P(A ∩ B) = 0. Draw a Venn or tree diagram first.
AI 4.7Discrete random variable📖 In the booklet
🧮 On your TI-Nspire CX II
⌨️ Type: sum(xlist · plist)
1.1*DocRADsum({0,1,2,3}·{0.1,0.3,0.4,0.2})1.7
💡 Fair game: E(gain) = 0.
AI 4.8Binomial distribution📖 In the booklet
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›6: Statistics›5: Distributions›A: Binomial Pdf… (=) / B: Binomial Cdf… (≤, ≥, between)
⌨️ Type: binomPdf(n,p,x) · binomCdf(n,p,lower,upper)
1.1*DocRADbinomPdf(10,0.3,3)0.266828binomCdf(10,0.3,0,3)0.649611binomCdf(10,0.3,4,10)0.350389
💡 P(X > 3) means lower bound 4 — integers! Write B(10, 0.3) in your working.
AI 4.9Normal distribution🧠 Learn by heart
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›6: Statistics›5: Distributions›2: Normal Cdf… / 3: Inverse Normal…
⌨️ Type: normCdf(lower,upper,μ,σ) · invNorm(area,μ,σ)
1.1*DocRADnormCdf(-9E999,52,50,4)0.691462invNorm(0.9,50,4)55.1262
💡 Enter σ (standard deviation), NOT σ². ‘−∞’ = −9E999. invNorm uses the area to the LEFT.
AI 4.10Spearman’s rank correlation🧠 Learn by heart
🧮 On your TI-Nspire CX II
rank each list by hand (ties: average rank)›Linear Regression on the ranks›read r
1.1*DocRADLinRegMx{1,2,3,4,5},{2,1,4,3,5},1Donestat.r0.8
💡 Spearman measures a monotonic (always up / always down) relationship.
AI 4.11χ² test for independence🧠 Learn by heart
🧮 On your TI-Nspire CX II
observed table as a matrix [⊞]›[menu]💻 click menu on keypad›6: Statistics›7: Stat Tests›8: χ² 2-way Test…
⌨️ Type: χ²2way [20,30;30,20]
1.1*DocRADχ²2way20303020Donestat.χ²4.stat.PVal0.0455003
💡 If any expected value < 5, combine rows/columns first. Reject H₀ if p < significance level.
AI 4.11χ² goodness of fit & t-test🧠 Learn by heart
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›6: Statistics›7: Stat Tests›7: χ² GOF… / 4: 2-Sample t Test… (Pooled: Yes)
1.1*DocRADχ²GOF{30,20,50},{25,25,50},2Donestat.χ²2.stat.PVal0.367879
💡 H₀ for t-test: μ₁ = μ₂. State hypotheses in words AND symbols.
Topic 5 ∫ Calculus6 cards
AI 5.2Increasing & decreasing🧠 Learn by heart
🧮 On your TI-Nspire CX II
Graphs page›graph f′ and look above/below the x-axis
AI 5.3Derivative of axⁿ📖 In the booklet
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›4: Calculus›1: Numerical Derivative at a Point…
⌨️ Type: d/dx(f(x))|x=a
1.1*DocRADddxx3−2·x|x=210
💡 The calculator gives a NUMBER (gradient at a point), not the formula f′(x).
AI 5.4Tangents & normals🧠 Learn by heart
🧮 On your TI-Nspire CX II
Graphs page›[menu]💻 click menu on keypad›6: Analyze Graph›5: dy/dx (gradient)›or Geometry → Points & Lines → Tangent
1.1*DocRADddxx3−2·x|x=21023−2·244−10·2-16
AI 5.5Integral of axⁿ & area📖 In the booklet
🧮 On your TI-Nspire CX II
[menu]💻 click menu on keypad›4: Calculus›2: Numerical Integral
⌨️ Type: nInt(f(x), x, a, b)
1.1*DocRAD20x2+1dx4.66667
💡 Area below the x-axis is negative — use |y| or split the integral.
AI 5.6Stationary points & optimisation🧠 Learn by heart
🧮 On your TI-Nspire CX II
Graphs page›[menu]💻 click menu on keypad›6: Analyze Graph›3: Maximum / 2: Minimum
1.1*DocRADnfMaxx·(20−2·x)2,x,0,103.333333.33333·(20−2·3.33333)2592.593
💡 Optimisation: write the function, differentiate, set f′ = 0, CHECK it is a max/min, answer in context.
AI 5.8Trapezoidal rule📖 In the booklet
🧮 On your TI-Nspire CX II
Lists & Spreadsheet›x-values in A›B = f(a[])›or type the formula
1.1*DocRAD0.52·(0+4+2·(0.25+1+2.25))2.75
💡 n = number of STRIPS, not number of points. Over-estimate if the curve is concave up.
✅ Next: open the Learn units for full step-by-step lessons on each topic. HL students: the HL version of this page has every SL and HL formula.
Booklet = the IB formula booklet for this course (first exams 2021, used until the new guide). TI-Nspire CX II (non-CAS) key paths may differ slightly by OS version.