1. The problem asks to find other trigonometric function values given one function value and the interval for $x$.
2. We will solve part (a) only, as per instructions to solve the first question only.
3. Given: $\frac{\pi}{2} < x < 0$ and $\sin x = -0.6$.
4. Note that the interval $\frac{\pi}{2} < x < 0$ is unusual since $\frac{\pi}{2} \approx 1.57$ and $0$ is less than $\frac{\pi}{2}$. Assuming the interval means $0 < x < \frac{\pi}{2}$ or $-\frac{\pi}{2} < x < 0$ (likely a typo), we proceed with $-\frac{\pi}{2} < x < 0$ because $\sin x$ is negative there.
5. Use the Pythagorean identity:
$$\sin^2 x + \cos^2 x = 1$$
6. Substitute $\sin x = -0.6$:
$$(-0.6)^2 + \cos^2 x = 1$$
$$0.36 + \cos^2 x = 1$$
7. Solve for $\cos^2 x$:
$$\cos^2 x = 1 - 0.36 = 0.64$$
8. Take the square root:
$$\cos x = \pm \sqrt{0.64} = \pm 0.8$$
9. Since $x$ is in the interval $-\frac{\pi}{2} < x < 0$, cosine is positive (cosine is positive in the fourth quadrant), so:
$$\cos x = 0.8$$
10. Calculate $\tan x$ using:
$$\tan x = \frac{\sin x}{\cos x} = \frac{-0.6}{0.8} = -0.75$$
11. Calculate $\cot x$ as reciprocal of $\tan x$:
$$\cot x = \frac{1}{\tan x} = \frac{1}{-0.75} = -\frac{4}{3}$$
12. Calculate $\sec x$ as reciprocal of $\cos x$:
$$\sec x = \frac{1}{0.8} = 1.25$$
13. Calculate $\csc x$ as reciprocal of $\sin x$:
$$\csc x = \frac{1}{-0.6} = -\frac{5}{3}$$
Final answers:
$$\cos x = 0.8$$
$$\tan x = -0.75$$
$$\cot x = -\frac{4}{3}$$
$$\sec x = 1.25$$
$$\csc x = -\frac{5}{3}$$
Trig Values F3C2Fd
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