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

• Nov 10th 2012, 02:22 PM
SoConfused123
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
• Nov 10th 2012, 02:33 PM
skeeter
Re: Simplify trig. expressions using identities? I would appericate any help given.
Quote:

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

...
• Nov 10th 2012, 02:47 PM
SoConfused123
Re: Simplify trig. expressions using identities? I would appericate any help given.
So would #1 be Cotan Beta?
And #4 be Tan theta?
• Nov 10th 2012, 02:53 PM
skeeter
Re: Simplify trig. expressions using identities? I would appericate any help given.
Quote:

Originally Posted by SoConfused123