Question

Help need for q13
Q17
And
Q19

Answer 1

19) sec + tan = p

On squaring both side we get

= (sec^2 + tan^2 + 2sec tan) = p^2

= 1/cos^2 + sin^2/cos^2 + 2(1/cos)(sin/cos) = p^2

= ( 1 + sin^2 + 2sin) / cos^2 = p^2

= (sin+ 1)^2 /( 1 - sin^2) = p^2

= (1+sin)(1+ sin) / (1+sin)(1 - sin) = p^2

= 1+sin / 1-sin = p^2

= 1 + sin = p^2 - p^2 sin

= 1 - p^2 = - sin - p^2sin

= 1 - p^2 = - sin (1 + p^2)

= p^2 - 1 / p^2 + 1 = sin


THANKS