Question

Find the cosine 315º. Round your answers to the nearest hundredth if necessary. 0 0.71 1 –0.78

Answer 1

cos 315° is about 0.71.

Answer 2

Cos(315) = 0.711.

Explanation:

Given : cosine 315º.

To find : Round your answers to the nearest hundredth.

Solution : We have given that cosine 315º.

Cos x = Sin (90- x).

Then

Cos ( 315) = Sin(90 -315)

Cos(315) = Sin (-225)

By the property Sin(-x) = -Sin(x)

Cos(315) = -Sin (225)

Cos (315) =
`(√(2))/(2)`

Cos(315) = 0.70711.

Therefore,Cos(315) = 0.711.