Question

cos(x+(pi/2))=-sinx verify the identity

Answer 1

\[\cos(x+(\pi/2))=-sinx\]

Answer 2

Recall that

\[\cos(A+B) = cosAcosB - sinAsinB\]

Answer 3

so solve for \[= cosxcos \frac{ \pi }{ 2 } - sinxsin \frac{ \pi }{ 2 }\]

Answer 4

so -sinx

Answer 5

?

Answer 6

yep that's right

Answer 7

alright great thank u !! can you help me with one more?

Answer 8

post it... i'll be around

Answer 9

alright