Question

-9cos pi /2+3sin pi /2-3ctg 5pi/4-5tg0

Answer 1

=-9*0+3*1-3*1-5*0=0
Ответ 0

Answer 2

Let's break down the expression step by step:

-9cos(pi/2) + 3sin(pi/2) - 3ctg(5pi/4) - 5tg(0)

First, let's evaluate the trigonometric functions:

cos(pi/2) = 0 sin(pi/2) = 1 ctg(5pi/4) = -1 (cotangent is the reciprocal of tangent, so ctg(5pi/4) = 1/tg(5pi/4) = 1/-1 = -1) tg(0) = 0

Substituting these values into the expression:

-9 * 0 + 3 * 1 - 3 * (-1) - 5 * 0

Simplifying further:

0 + 3 + 3 - 0

Finally:

6

Therefore, the value of the expression -9cos(pi/2) + 3sin(pi/2) - 3ctg(5pi/4) - 5tg(0) is 6.