Helen's Blog #5

I'll be going over section 8-5.

First you would have to see if your problem has the same inverse, if it doesn't then you would use the identities to get to the same trig function. If you can't you would have to try to make it tan or cot by (sin/cos) or (cos/sin).

Then you would follow the inverse rules.

THINGS YOU CAN'T DO!:

1: Divide by a trig function when you are solving to cancel.
2: Cancel from the inside of a trig function.

Sin (2x)

2 * You can't cancel the 2

Sin ²x= Sin * You can't divide and cancel

Examples:

2 Sin ² θ-1 =0

2 Sin ² θ=1
Sin ² θ= ½
Sin θ= +/- Sq. root of ½
θ= Inverse Sin (Sq. root of ½)

QI: 45°
QII: 135°
QIII: 225°
QIV: 315°