Question

answer nhi aa raha h ​

Answer 1

❒ answer

➥cosec10°-4sin(70°)=2.828≈3

Answer 2

Answer:

cosec10 - 4sin70

= 1/sin10 - 4sin70

= (1 - 4sin70 * sin10)/sin10

= (1 - 2 * 2sin70 sin10)/sin10

= (1 - 2(cos60 - cos80))/sin10, cosA - cosB = -2sin[(A + B)/2] sin[(A - B)/2]

= (1 - 2cos60 + 2cos80)/sin10

= (1 - 2(1/2) + 2cos80)/sin10

= (1 - 1 + 2cos80)/sin10

= 2cos80 / sin10

= 2cos80 / cos(90 - 10), sinA = cos(90 - A)

= 2cos80 / cos80

= 2