# if sec theta+tan theta =p ,prove that sin theta = (p square- 1) / (p square + 1)

= Taking R.H.S i.e, (p2-1) / (p2+1)

= Putting value of p in given equation

= [(sec0+tan0)2-1] / [(sec0+tan0)2+1]

= (sec20+tan20+2sec0tan0-1) / (sec20+tan20+2sec0tan0+1)

= (sec20-1)+tan20+2sec0tan0 / (1+tan20)+sec20+2sec0tan0

= tan20+tan20+2sec0tan0 / sec20+sec20+2sec0tan0 [ As sec20-1=tan20 1+tan20=sec20 ]

= 2tan20+2sec0tan0 / 2sec20+2sec0tan0

= 2tan0+(tan0+sec0) / 2sec0+(sec0+tan0) [ Taking 2tan0 2sec0 as common ]

= tan0 / sec0 [ 2 and tan0+sec0 gets cancelled above ]

= sin0/cos0 / 1/cos0 [ As tan0=sin0/cos0 and sec0=1/cos0 ]

= sin0/1

= sin0

= L.H.S

Hence Proved...........

• 86
it is there in RD SHARMA
• -24

• 36
Hope this helps !

• 247
Hope this helps 👍

• 18
Hi thanks....ppl
• -12
Hope it will help cheers!!!

• 6

• -11
Solution

• 12
yes
• -10
sec theta + tan theta =p
sec theta - tan theta =1/p
2 sec theta =pSq+1/p
2 tan theta =pSq-1/p
2 tan theta/2 sec theta =pSq-1/pSq+1
hence ,proved
• 3
Ans

• 11
Hi.Your school is my centre of examination.
• -6
Hi; your school is my centre of examination.
• -4
Hope it helps....

• 3
What are you looking for?