Question

how to know the value of cos 135​

Answer 1

Answer:

cos 135=cos (90+45)

=cos90 .cos45 -sin90.sin45

0.1/√2 -1.1/√2= -1/√2

Answer 2

The value of cos135 is −1√2.

☞We have cos135.

135=3π4

So

cos(3π4)=cos(π−π4)

=−cos(π4)

=−1√2

Hope it helps!!