Question

Какая из функций является четной: А. y=2cosx; B. y=1,5sinx; C. y=x; D. y=tgx?

Answer 1

Ответ А , потому что всегда cos(-x) равняетсЯ cosx

Answer 2

Function Parity Analysis

Let's analyze each function to determine which one is even:

A. y = 2cosx: This is an even function because it satisfies the condition f(x) = f(-x). The cosine function is symmetric about the y-axis, so it is an even function.

B. y = 1.5sinx: This is an odd function because it satisfies the condition f(x) = -f(-x). The sine function is symmetric about the origin, so it is an odd function.

C. y = x: This is neither an even nor an odd function. It is a linear function and does not satisfy the conditions for even or odd functions.

D. y = tgx: The tangent function is an odd function because it satisfies the condition f(x) = -f(-x). Therefore, y = tgx is an odd function.

Based on the analysis, the even function is y = 2cosx (Option A).