And the last one..... I think you mean to find the other trig ratios given the sine ratio of an angle, and given the cosine of another angle. Is that right?

[4] \(\displaystyle \sin u=\frac{3}{5}=\frac{y}{r}\)

Use Pythagoras to find x: \(\displaystyle 5^2=x^2+3^2\)

Then, fill in the remaining ratios (could be in QI or QII).

\(\displaystyle \tan u=\frac{y}{x} \: \: \: \cot u = \frac{x}{y}\)

\(\displaystyle \cos u=\frac{x}{r} \: \: \: \sec u = \frac{x}{r}\)

\(\displaystyle \sin u=\frac{y}{r} \: \: \: \csc u = \frac{r}{y}\)

Do something similar with \(\displaystyle \cos u = \frac{7}{25}\). Could be in QI or QIV.