Small Angles Approximations

Question 1

What do you use when finding a small angle approximation for sin?

Answer 1

sin x ≈ x

Question 2

What do you use when finding a small angle approximation for cos?

Answer 2

cos x ≈ 1 - x^2/2

Question 2

What do you use when finding a small angle approximation for tan?

Answer 2

tan x ≈ x

Question 3

How would you find an approximation for Cos 0.2?

Answer 3

Cos 0.2 ≈ 1 - (0.2)^2/2
≈ 0.98

Question 3

How would you find an approximation for Cos x + 10sin15x = 0

Answer 3

≈ 1 - x^2/2 + 10(15x) = 0