If $$2\sec^2 x - \tan^2 x = 5 and 0^\circ \leq x \leq 90^\circ$$ then $$x=?$$
$$2\sec^2 x - \tan^2 x = 5$$
$$\sec^2x+\sec^2x-\tan^2x=5$$
$$1+\sec^2x=5$$ Â ($$\sec^2x-\tan^2x=1$$)
$$\sec^2x=4$$
$$^{\sec^260^{\circ\ }=4\ \left(\sec60^{\circ\ }=2\right)}$$
Create a FREE account and get: