solving trig functions :)

This week in class we learned about how to solve a trig function.

1.) Isolate the trig function.

2.) Take the inverse of the trig function. (Examples sin^-1, cos^-1)

*** An inverse finds an angle.

3.) Use trig chart or calculator to find answer (only use value)

4.) Use quadrants to find the right angle positive or negative with trig function.

Examples:

1.) solve for theta(q)

5 cos q + 9 = 7

-9 -9

5 cos q = -2

/5 /5

cos q = -2/5

q=cos^-1 (-2/5)= 66.422 (you can’t use this one because cos is negative in quadrant two and three not one.)

so to move to quadrant two from one you have to make negative and add 180 which =113.578 ( this is one of your answers)

to find your second answer you have to take 66.422 and add 180 to get your third quadrant answer, which = 246.422 ( this is your other answer)

q=113.578 and 246.422 ( you can’t leave it like this because it has to be in degrees, minutes and seconds)

.578*60 = 34

.68 * 60 = 40

= 113 degrees 34 minutes and 40 seconds

.422* 60 = 25

.32 * 60 = 19

= 246 degrees 25 minutes and 19 seconds

q = 113 degrees 34 minutes and 40 seconds and 246 degrees 25 minutes and 19 seconds