How do you simplify #cos(x+pi/2)#?

1 Answer
Write your answer here...
Start with a one sentence answer
Then teach the underlying concepts
Don't copy without citing sources
preview
?

Answer

Write a one sentence answer...

Answer:

Explanation

Explain in detail...

Explanation:

I want someone to double check my answer

Describe your changes (optional) 200

12
Sep 30, 2016

Use the known trigonometric identity

#cos(a+b)=cosa*cosb-sina*sinb#

we have that

#cos(x+pi/2)=cosx*cos(pi/2)-sinx*sin(pi/2)=cosx*0-sinx*1=-sinx#

Finally

#cos(x+pi/2)=-sinx#

Was this helpful? Let the contributor know!
1500