Question

if A = 30°, show that: 1 - cosA/sin² = tanA
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Answer 1

Answer:

To prove : secA1+secA=1−cosAsec12A

LHS secA1+secA=cosA11+cosA1

=cosA1cosAcosA+1

=cosAcosA+1×1cosA

=1+cosA

=1+cosA×1−cosA1−cosA

=1−cosA(1)2−(cosA)2

=1−cosA1−cos2A

=1−cosAsin