prove that 1+secA /sec A = sin ^2 A / 1- cos A
Answers
Answer:
Step-by-step explanation:
rove that 1+secA /sec A = sin ^2 A / 1- cos A
Step-by-step explanation:
Taking LHS,
LHS=\frac{1+\sec A}{\sec A}LHS=
secA
1+secA
Substitute, \sec A=\frac{1}{\cos A}secA=
cosA
1
LHS=\frac{1+\frac{1}{\cos A}}{\frac{1}{\cos A}}LHS=
cosA
1
1+
cosA
1
LHS=\frac{\frac{\cos A+1}{\cos A}}{\frac{1}{\cos A}}LHS=
cosA
1
cosA
cosA+1
LHS=\frac{\cos A+1}{\cos A}\times \cos ALHS=
cosA
cosA+1
×cosA
LHS=\cos A+1LHS=cosA+1
Multiply and divide by \cos A-1cosA−1
LHS=(\cos A+1)\times \frac{\cos A-1}{\cos A-1}LHS=(cosA+1)×
cosA−1
cosA−1
LHS=\frac{(\cos A+1)(\cos A-1)}{\cos A-1}LHS=
cosA−1
(cosA+1)(cosA−1)
LHS=\frac{\cos^2 A-1^2}{\cos A-1}LHS=
cosA−1
cos
2
A−1
2
LHS=\frac{-\sin^2 A}{\cos A-1}LHS=
cosA−1
−sin
2
A
LHS=\frac{\sin^2 A}{1-\cos A}LHS=
1−cosA
sin
2
A
LHS=RHSLHS=RHS
Hence proved.