cot 2α + csc 2α

α is gelijk aan
A.   sin α
B.   cos α
C.   tan α
D.   cot α
E.   sec α
    A   B   C   D   E

[ 5-7380 - op net sinds 17.12.2025-(E)-16.10.2026 ]

Translation in   E N G L I S H

cot 2α + csc 2α

is equal to

Oplossing - Solution

\(\large\cot 2\alpha+\csc2\alpha=\frac{1}{\tan 2\alpha}+\frac{1}{\sin 2\alpha}=\frac{1-\tan^2\alpha}{2\tan{\alpha}}+\frac{1}{2\sin{\alpha}\cos{\alpha}}\) \(\Large=\frac{(1-\tan^2\alpha)\cos\alpha}{2\sin\alpha}+\frac{1}{2\sin\alpha.\cos\alpha}=\frac{(1-\tan^2\alpha)\cos^2\alpha+1}{2\sin\alpha\cos\alpha\alpha}\) \(\Large=\frac{\cos^2\alpha-\sin^2\alpha+1}{2\sin\alpha\cos\alpha}=\frac{2\cos^2\alpha}{2\sin\alpha\cos\alpha}=\frac{\cos\alpha}{\sin\alpha}=\cot\alpha\)

GWB