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Statement-1: (cos36^(@)-cos72^(@))/(cos...

Statement-1: `(cos36^(@)-cos72^(@))/(cos36^(@)cos72^(@))=2`
Statement-2: `sin15^(@)=(sqrt6-sqrt7)/(4)`

A

Statement-1 is True, Statement-2 is true, Statement-2 is a correct explanation for Statement -1.

B

Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for Statement-1.

C

Statement-1 is True, Statement-2 is False.

D

Statement-1 is False, Statement-2 is True.

Text Solution

Verified by Experts

The correct Answer is:
C
We have,
`(cos36^(@)-cos72^(@))/(cos36^(@)cos72^(@))=(cos36^(@)-sin18^(@))/(cos36^(@)sin18^(@))=((sqrt5+1)/(4)-(sqrt5-1)/(4))/((sqrt5+1)/(4)xx(sqrt5-1)/(4))=2`
So, statement-1 is true.
`sin15^(@)=sin(45^(@)-30^(@))=(sqrt3-1)/(2sqrt2)=(sqrt6-sqrt2)/(4)`
So, statement-2 is also true. But it is not a correct explanation for statement-1.
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