Thread: Simplify trig. expressions using identities? I would appericate any help given.

1.Simplify:
Cos(3pi/2-Beta)

I have no idea how to solve?

2.Simplify:
(secB-1)(Sec B+1)

Would the answer be -tan²B ?

3. Simplify: fractions
1+sin x cos x
_____ + _____
cos x 1+sin x

Would the answer be 2 sec x ?

4: Simplify:
1-(sin theta - cos theta)²
____________________
sin theta

Originally Posted by SoConfused123

1.Simplify:
Cos(3pi/2-Beta)

I have no idea how to solve?

cos(a-b) = cos(a)cos(b)+sin(a)sin(b)

2.Simplify:
(secB-1)(Sec B+1)

Would the answer be -tan²B ?

+tan²(b)

3. Simplify: fractions
1+sin x cos x
_____ + _____
cos x 1+sin x

Would the answer be 2 sec x ?

yes

4: Simplify:
1-(sin theta - cos theta)²
____________________
sin theta

I cannot get pass

1- sin² theta - cos² theta
____________________
sin theta

uhh ... (sint - cost)² = sin²t - 2sint cost + cos²t

...

Thank you for your help.
So would #1 be Cotan Beta?
And #4 be Tan theta?

Originally Posted by SoConfused123

Thank you for your help.

So would #1 be Cotan Beta? no ... it would be -sin(b)

And #4 be Tan theta and no ... it would be 2cos(t)

...

Oh...I'm horrible at this.
Well thank you.