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IBDP Mathematics: Functions and Trigonometry

Functions and Trigonometry

September 12, 2022

Trigonometric Identities

In IB Mathematics, there are trigonometric identities as follows.

  • sec x = 1/cos x
  • cosec x = 1/sin x
  • cot x = 1/tan x
  • tanθ = sinθ/ cosθ
  • cos2θ + sin2θ = 1
  • 1 + tan2θ = sec2θ
  • cot2θ + 1 = cosec2θ

Note: When asked to show by counter-example that a statement is false, sub a value in and show that LHS is not equal to RHS.

Formulae for sin (A + B), cos (A + B), tan (A + B)

Sin (A + B) = sin A cos B + cos A sin B

Sin (A - B) = sin A cos B - cos A sin B

Cos (A + B) = cos A cos B - sin A sin B

Cos (A - B) = cos A cos B + sin A sin B

Transformations of Graphs

When it comes to IB Mathematics, the transformations so far follow these rules:

  • f(x) + a is f(x) shifted upward a units
  • f(x) – a is f(x) shifted downward a units
  • f(x + a) is f(x) shifted left a units
  • f(x – a) is f(x) shifted right a units
  • f(x) is f(x) flipped upside down ("reflected about the x-axis")
  • f(–x) is the mirror of f(x) ("reflected about the y-axis")

Functions

Graphs of Functions

This is the end of this topic.