Question

Given sin x = 0.9 , what is cos x ? Enter your answer as a decimal in the box. Round only your final answer to the nearest hundredth.

Answer 1

`cos(x)=(+/-)0.44`

Explanation:

we know that

`sin^(2)(x)+cos^(2)(x)=1`

In this problem we have

`sin(x)=0.9`

substitute and solve for cos(x)

`0.9^(2)+cos^(2)(x)=1`

`cos^(2)(x)=1-0.9^(2)`

`cos^(2)(x)=0.19`

`cos(x)=(+/-)0.44`