Questions in the description.

Question

1) If cos x=0.25, find sin x

A) sin x ≈ 0.03

B) sin x ≈ 0.75

C) sin x ≈ 0.97

D) sin x ≈ 0.0625

2) If tan x = 0.5, find cos x

A) cos x ≈ 0.89

B) cos x ≈ 0.11

C) cos x ≈ 1.25

D) cos x ≈ 1.12

3) Which of the following are considered tiginomic identities? Select all that apply.

A) sec^2x = tan^2 x+1

B) sin^2x +cos^2x=1

C) 1+sin^2x =cos^2x

D) 1+cot^2 x= csc^2x

Answer 1

1)c when cosx is small, sinx is large; a & d are definitely wrong

2)a. c&d are impossible. cosx is never larger than 1 or less than -1

3)a,b,& d,

sin^2(x) + cos^2(x) = 1 is the most known identity which is a) It's similar to a unit circle with hypotenuse =1 and sides = x and y, x^2 + y^2 = 1, which is the same as sin^2(x) + cos^2(x) = 1

divide a) by cos^2x gives b)