SA3 marksYear: 2020MediumCBSE Class 10
trigonometryidentitiesproof
Question
Prove that: 1−sinA1+sinA=secA+tanA Solution
1
LHS =1−sinA1+sinA=(1−sinA)(1+sinA)(1+sinA)(1+sinA) +0.5 marks2
=1−sin2A(1+sinA)2=cos2A(1+sinA)2 +1 mark3
=cosA1+sinA=cosA1+cosAsinA
+1 mark4
=secA+tanA= RHS
+0.5 marks