Cos square 30 degree cos square 45 degree + 4 sec square 60 degree + 1/2 cos square 90 degree - 2 tan square 60 degree

Answer 1

what is the question?

Answer 2

cos^2 30° cos^2 45° + 4sec^2 60° + (1/2)cos^2 90° - 2tan^2 60°

these are all special angles and you should memorize the trig ratios of the 30-60-90 and the 45-45-90 triangles

= (√3/2)^2 (1/√2)^2 + 4(2)^2 + (1/2)(0) - 2(√3)^2
= (3/4)(1/2) + 16 + 0 - 2(3)
= 3/8 + 16 - 6
= 10 3/8 or 83/8

Answer 3

cos 90 = 1/root 2 not 0

Answer 4

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Answer 5

Thanks for help ....... Good .... Nice experience 🥰🥰

Answer 6

anonymous cos 90 is 0 itself
Reiny gave the correct answer
the answer is right