\( 4tanx-ctgx=0 \)

2. a) Verify that \( \frac{\cos x}{1-\sin x}=\frac{1+\sin x}{\cos x} \) is true for \( x=\frac{\pi}{4} \). b) What are the non-permissible values for the equation?

\( 4tanx-ctgx=0 \)

-pi/3 on the unit circle

(iii) यदि \( \tan (\mathrm{A}+\mathrm{B})=\mathrm{p} \) तथा \( \tan (\mathrm{A}-\mathrm{B})=\mathrm{q} \) : तो \( \tan 2 \mathrm{~A} \) का मान ज्ञात कीजिए। \[ \text { If } \tan (\mathrm{A}+\mathrm{B})=\mathrm{p} \text { and } \tan (\mathrm{A}-\mathrm{B})=\mathrm{q} \text {; then find the value of } \tan 2 \mathrm{~A} \text {. } \]

The angle of elevation of the Sun is \( 33.1^{\circ} \) at the instant the shadow cast by a monument is 720 feet long. Use this information to calculate the height of the monument. The height of the monument is \( \square \mathrm{ft} \). (Round to two decimal places as needed.)