# Math Help - Trig Identities

1. ## Trig Identities

Long time no see. This is actually for my roomate and we have not been able to solve this problem

Secant X = CosineX + SinX x TangentX

Any help is appreciated

Nm thanks

2. ## NEW one to TRY

Can you try to figure this one?

cscx - sinx= (cotx/secx)

3. $sec(x)=cos(x)+sin(x)tan(x)$

Let's turn the right into the left:

$cos(x)+sin(x)\cdot\frac{sin(x)}{cos(x)}$

$cos(x)+\frac{sin^{2}(x)}{cos(x)}$

$\frac{cos^{2}(x)+sin^{2}(x)}{cos(x)}$

As you should know, the numerator is equal to 1 and we have:

$\frac{1}{cos(x)}=sec(x)$

4. $csc(x)-sin(x)=\frac{cot(x)}{sec(x)}$

$\frac{1}{sin(x)}-sin(x)=\frac{\frac{cos(x)}{sin(x)}}{\frac{1}{cos(x )}}$

$\frac{1-sin^{2}(x)}{sin(x)}=\frac{cos^{2}(x)}{sin(x)}$

$\frac{cos^{2}(x)}{sin(x)}=\frac{cos^{2}(x)}{sin(x) }$