Question

-sin pi/2 + 2 ctg 3pi/4​

Answer 1

Відповідь:

-3

Пояснення:

sinπ/2+2ctg3π/4=-1-2=-3

Answer 2

Ответ: -3

Объяснение:

-sin π/2 + 2ctg 3π/4 = -sin (90°)+2(135°)=-1+2(-1)=-3

Answer 3

Let's calculate the expression:

-sin(pi/2) + 2 * ctg(3pi/4)

First, let's calculate the values of the trigonometric functions:

1. sin(pi/2) = 1
2. ctg(3pi/4) = 1/tan(3pi/4)

Now, we need to find the value of tan(3pi/4). To do that, we can first find the value of tan(pi/4) and then take its reciprocal.

1. tan(pi/4) = 1

So,

tan(3pi/4) = -tan(pi/4) = -1

Now, we can calculate ctg(3pi/4):

ctg(3pi/4) = 1/tan(3pi/4) = 1/(-1) = -1

Now, we can substitute these values into the original expression:

-sin(pi/2) + 2 * ctg(3pi/4) = -1 + 2 * (-1) = -1 - 2 = -3

So, the value of the expression is -3.