Question

Evaluate 5sin50° sec40°-3 cos59°cosec31°.

Answer 1

Answer:

2

Explanation:

Use the images given below for better visual clarity.

5 sin50°sec40° - 3 cos59°cosec31°

=> 5 sin50°(1/cos40°) - 3 cos59°(1/sin31°)           [secФ° = 1/sinФ°, cosecФ° = 1/cosФ°]

=> 5 sin50°(1/cos{90° - 50°}) - 3 cos59°(1/sin{90° - 59°})           [sin(90° - Ф°) = cosФ°, cos(90° - Ф°) = sinФ°]

=> 5 sin50°(1/sin50°) - 3 cos59°(1/cos59°)

=> 5(1) - 3(1) => 5 - 3 => 2

Answer 2

Step-by-step explanation:

5 sin 50° / cos 40° - 3 cos 59° /sin 31°

5 sin 50°/ cos (90° - 50°) - 3cos 59° / sin (90° - 59°)

5 sin 50° / sin 50° - 3 cos 59°/cos 59°

5 - 3 = 2