Question

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

Answer 1

The answer is 0.44. I don't know how it got there but that was the answer that the quiz said was correct lol

Answer 2

It is given sinx=0.9 .We need to find cosx.

We use the identity :

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

Substituting sinx=0.9

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

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

Substracting 0.81 both sides:

`cos^(2) x =1-0.81`

`cos^(2) x=0.19`

Taking root of both sides cosx=0.435

Rounding to nearest hundredth

cosx=0.44.