The first answer is B
The second answer is D
Suppose we let
, so that
.
Also, recall the double angle identity for cosine:

So, we can rewrite and compute the integral using the substitution, as





Answer: The height of the mountain is 1,331.4 meters (approximately)
Step-by-step explanation: From the information given, the students were standing at point b which is 800 meters from the base of the mountain and the angle of elevation from that point is 59°. Assuming that the ground is level, we can derive a right angled triangle from this set of details and hence we have triangle ABC, where angle β is the reference angle, (59 degrees), BC is the distance from the students to the base of the mountain (800 meters) and the line AC is the height of the mountain.
The line AC is the opposite, since angle B is the reference angle, therefore we shall use the trigonometric ratio as follows;
Tan β = opposite/adjacent
Tan 59 = AC/800
Tan 59 x 800 = AC
1.6643 x 800 = AC
1331.44 = AC
AC ≈ 1331.4
Therefore the height of the mountain is approximately 1,331.4 meters
Answer: b
Explanation:
The line of best fit to a scattergram is obtained in linear regression analysis by minimizing the sum of the squared errors.
For example, in the diagram shown below, there are n data points in the scattergram.
The error for the i-th data point is

.
The coefficients (a and b) for the line of best fit are determined using calculus, to minimize

.