Sign in
Please select an account to continue using cracku.in
↓ →
If $$\sec^2 x - 3 \sec x + 2 = 0$$, then the value of $$x(0 < x < 90^\circ)$$ is:
$$\sec^2 x - 3 \sec x + 2 = 0$$
$$=$$> $$\sec^2x-2\sec x-\sec x+2=0$$
$$=$$> $$\sec x\left(\sec x-2\right)-1\left(\sec x-2\right)=0$$
$$=$$> $$\left(\sec x-2\right)\left(\sec x-1\right)=0$$
$$=$$> $$\sec x-2=0$$ or $$\sec x-1=0$$
$$=$$> $$\sec x=2$$ or $$\sec x=1$$
$$=$$> $$\cos x=\frac{1}{2}$$ or $$\cos x=1$$
$$=$$> $$\cos x=\cos60^{\circ\ }$$ or $$\cos x=\cos90^{\circ\ }$$
$$=$$> $$x=60^{\circ\ }$$ or $$x=90^{\circ\ }$$
Since $$(0 < x < 90^\circ)$$
$$\therefore\ $$ $$x=60^{\circ\ }$$
Hence, the correct answer is Option C
Create a FREE account and get: