Login

25sin2 A+10cos2A=15,then cot2A=?

25sin2A +10cos2A=15 cot2A=?

25(1-cos2A)+10cos2A=15

25-25cos2A+10cos2A=15

-15cos2A=-10

cos2A=2/3

RHS=cot2A

=cos2A/sin2A

=cos2A/1-cos2A

=2/3 / 1-2/3

=2/3 /1/3

=6/3

=2

  • 2
View Full Answer

(here fr example cot2A means cot squared A)

25sin2A+10 cos2A=15*1

25 sin2A+10cos2A =15(sin2A+cos2A) (sin2A+cos2A=1)

25 sin2A+10cos2A= 15sin2A+15cos2A

when we simplify we get,

10 sin2A = 5 cos2A

10/5= cos2A/sin2A

2 = cot2A (cos2A/sin2A=cot2A)

therefore cot2 A=2

hope it hlpzzzzzzzzz ..... thumbs up plzzzzzzzzzzz

  • 0

(here fr example cot2A means cot squared A)

25sin2A+10 cos2A=15*1

25 sin2A+10cos2A =15(sin2A+cos2A) (sin2A+cos2A=1)

25 sin2A+10cos2A= 15sin2A+15cos2A

when we simplify we get,

10 sin2A = 5 cos2A

10/5= cos2A/sin2A

2 = cot2A (cos2A/sin2A=cot2A)

therefore cot2 A=2

hope it hlpzzzzzzzzz ..... thumbs up plzzzzzzzzzzz

  • 1
What are you looking for?