Answer:
see explanation
Step-by-step explanation:
Using the trigonometric identities
cot A = [tex]\frac{cosA}{sinA}[/tex], tanA = [tex]\frac{sinA}{cosA}[/tex], cscA = [tex]\frac{1}{sinA}[/tex], secA = [tex]\frac{1}{cosA}[/tex]
Consider the right side
[tex]\frac{cotA-tanA}{cscAsecA}[/tex]
= [tex]\frac{\frac{cosA}{sinA}-\frac{sinA}{cosA} }{\frac{1}{sinA}.\frac{1}{cosA} }[/tex]
= [tex]\frac{\frac{cos^2A-sin^2A}{sinAcosA} }{\frac{1}{sinAcosA} }[/tex]
= [tex]\frac{cos^2A-sin^2A}{sinAcosA}[/tex] × sinAcosA ( cancel sinAcosA )
= cos²A - sin²A
= cos2A
= left side ⇒ verified
