Question

Где ошибка в моих вычислениях sin30°-cos²30+ctg45°? sin30°-cos²30+ctg45°=1/2-3/2+1 = -2/2+1/1 = -1/3

Answer 1

Ответ:

Пошаговое объяснение:

На фото

Answer 2

Looks like there might be a mistake in your calculations. Let's go through it step by step:

$\sin(30^\circ) - \cos^2(30^\circ) + \cot(45^\circ)$

1. $\sin(30^\circ)$ is $\frac{1}{2}$.
2. $\cos(30^\circ)$ is $\frac{\sqrt{3}}{2}$, so $\cos^2(30^\circ)$ is $\frac{3}{4}$.
3. $\cot(45^\circ)$ is $1$.

Now, let's substitute these values into your expression:

$\frac{1}{2} - \frac{3}{4} + 1$

To add these fractions, find a common denominator, which is 4 in this case:

$\frac{2}{4} - \frac{3}{4} + \frac{4}{4}$

Now add the numerators:

$\frac{2 - 3 + 4}{4}$

Combine the numerators:

$\frac{3}{4}$

So, the correct result is $\frac{3}{4}$, not $-\frac{1}{3}$. It appears there was a sign error in your intermediate steps.