Синус острого угла А треугольника АБС равен √7/4 найдите соs угол А

To find the cosine of angle A, we can use the Pythagorean identity:

cos^2(A) + sin^2(A) = 1

Given that the sin(A) = √7/4, we can substitute this value into the equation:

cos^2(A) + (√7/4)^2 = 1

cos^2(A) + 7/16 = 1

cos^2(A) = 1 - 7/16

cos^2(A) = 9/16

Now, taking the square root of both sides gives us:

cos(A) = ±√(9/16)

cos(A) = ±3/4

Therefore, the cosine of angle A is ±3/4.