Find M in \int_{-\frac{\pi}{2}}^{M} \cos x dx= 1.5 with Expert Tips

[ziddy83]

Hey what's up..I need a little help with the following problem.

If $$\int_{-\frac{\pi}{2}}^{M} \cos x dx= 1.5}$$, find M.

How do I go about doing this? I know that...the anti derivative of cos is sin, and that $$\sin x \right]_{-\frac{pi}{2}}^{M} = 1.5$$

Any help would be greatly appreciated...

 

[James R]

$$\sin x |^M_{-\pi/2} = \sin M - (-\pi/2) = 1.5$$

Are you ok from there?

 

[ziddy83]

ahhh..DUH! goshh...how did i NOT see that? Thanks man...haha...

 

[dextercioby]

It was a typo/error in post #2.

$$\sin x\left |_{-\frac{\pi}{2}}^{M}\right =1.5\Rightarrow \sin M+\sin\frac{\pi}{2}=1.5\Rightarrow \sin M +1 =1.5$$

Daniel.

 

[James R]

Oops! You're right, of course.