The Purplemath Forums

by **mannilea** on Wed Sep 09, 2009 2:36 pm

hi wasnt sure whether the two questions should be together or seperate sorry if they were meant to got together

solve the equation 3 sec^2 pheta +7= 11 tan pheta giving all values of x to 3sf in the interval 0<pheta<2pi

sorry for the bad setting out dont no how to get pheta and pi signs

thanks for any help

**Sponsor**

by **stapel_eliz** on Wed Sep 09, 2009 6:36 pm

Does "pheta" perhaps mean "theta", written as " $\theta$ "...? :oops:

Since the square of the secant can be related to the tangent, a good first step would probably be to replace $\sec^2(\theta)$ with $1\, +\, \tan^2(\theta)$ , and proceed with solving the resulting quadratic equation in tangent. :wink:

The Purplemath Forums

solving the equation 3 sec^2 pheta +7= 11 tan pheta

solving the equation 3 sec^2 pheta +7= 11 tan pheta