Hello starrytulips143 Originally Posted by
starrytulips143 2cosx - secx = - tanx
thank you in advance.
i need to solve the equation and give an answer in radians.
Here are the steps to take; I'll leave the details to you:
- Using $\displaystyle \sec x = \frac{1}{\cos x}$ and $\displaystyle \tan x = \frac{\sin x}{\cos x}$, express everything in terms of sine and cosine.
- Multiply both sides by $\displaystyle \cos x$ to get rid of fractions.
- Then use $\displaystyle \cos^2x+\sin^2x=1$ to express everything in terms of $\displaystyle \sin x$.
- Re-arrange as a quadratic in $\displaystyle \sin x$.
- Factorise. You should get:
$\displaystyle (2\sin x+1)(\sin x -1)=0$
Can you complete it now?
Grandad