(1.0×10^−15)/(4.2×10^−7) answer in two sig figs

In part i, the independent variable, the one that is intentionally manipulated, in part ii, the independent variable changes the dependent variable, the one you measure the response in, is the same for parts i and ii. for both parts of the lab, the dependent variable

Solve 2 - 3 cos x = 5 + 3 cos x for 0° ≤ x ≤ 180° a. 150° b. 30° c. 60° d. 120°

Suppose a laboratory has a 30 g sample of polonium-210. the half-life of polonium-210 is about 138 days how many half-lives of polonium-210 occur in 1104 days? how much polonium is in the sample 1104 days later? 9; 0.06 g 8; 0.12 g 8; 2,070 g