Friday

November 28, 2014

November 28, 2014

Posted by **lindsay** on Tuesday, May 1, 2012 at 4:30pm.

- trigonometry -
**Reiny**, Tuesday, May 1, 2012 at 4:38pm4 tan^2 x + 12 sec x +1 =0

4sin^2 x/cos^2 x + 12/cosx + 1 = 0

times cos^2 x

4sin^2x + 12cosx + cos^2x = 0

4(1-cos^2 x) + 12cosx + cos^2 x = 0

-3cos^2 x + 12cosx + 4 = 0

3cos^2 x - 12cosx - 4 = 0

cosx = (12 ± √192)/6

= 4.309.. which is not possible, or cosx = -.3094..

so x must be in quads II or III

x = 180-71.977° or x = 180+71.977

x = 108.02° or 251.98°

**Answer this Question**

**Related Questions**

algebra/trigonometry - What are the values of theta in the interval 0degrees ...

Calculus - Determine the measure of A if 0 degrees is less or equal to angle A ...

Trigonometry - Solve for the following equation to the nearest degree if needed ...

trig - tan theta= square root of 3 / 3 if o degrees is less than or equal to ...

Calculus - Fine the measure of feta, to nearest degree, where 0 degrees is less ...

trig - what are the values of theta in the interval 0 degrees is lessthan or ...

Math - Solving Trig Equations - Solve each equation for 0 is less than and equal...

trig - how do i get the degree for (tan+1)(tanx-2)=0 in the interval of 0 is ...

trigonometry - Solve the equation 6 cos x^2+sin x=4 if 0 is less than or equal ...

Trig - Solve the equation on the interval 0 less than or equal 0 < 2pi. 1. ...