+91-87964 74404
FlagBACK
Question icon
Grade 11Trigonometry

2)COS12 – SIN12 /CO12+SIN12 + SIN147/ COS147
  1. 1
  2. -1
  3. 0
  4. NONE

Profile image of KRISHA SHETH
8 Years agoGrade 11
Answers icon

1 Answer

Profile image of Arun
8 Years ago
Dear Krisha
 
[cos(90-78) - sin12/ cos(90-78) + sin12 ] + sin147/cos147]
 
= [sin78 - sin12]/[sin78 + sin12]  +sin(180-33)/cos(180-33)
 
= [(2 cos 45 sin 33)/(2 sin 45 cos33)] + sin 33/(-cos 33)
 
Since cos 45 = sin 45, hence they can be cancelled
 
= Sin 33/ cos33  - sin 33/cos33
= 0
 
Regards
Arun (askIITians forum expert)

Other Related Questions on trigonometry

question mark
In ABC, if cot A+cot B+cot C = cosecA cosecB cosecC, then prove that ABC is right angle triangle.
trigonometry
1 Answer Available

Last Activity: 3 Years ago

question mark
  • Find the general solution of equation tan3∂=cot2∂
For all angles between -720 and +720
trigonometry
1 Answer Available

Last Activity: 4 Years ago

question mark
To prove : Cosec(45 degree - A)Cosec(45 degree + A) = 2SecA
trigonometry
1 Answer Available

Last Activity: 4 Years ago

question mark
Derive a formula for the area of the triangle, given b, A, B, and C. That is, derive the formula: (b^2sinAsinC)/(2sinB)
trigonometry
1 Answer Available

Last Activity: 4 Years ago

question mark
WHAT IS THE LIMIT WHEN X TOWARDS TO 0 OF sin6x/5x ? lim𝑥→0 𝑠𝑖𝑛6𝑥/5𝑥 
trigonometry
1 Answer Available

Last Activity: 4 Years ago