Given the general identity tan x =sin x/cos x , which equation relating the acute angles, a and c, of a right ∆abc is true?

a. tan a = sin a/sin c
b. cos a = tan (90-a)/sin (90-c)
c. sin c = cos a/tan c
d. cos a = tan c
e. sin c = cos (90-c)/tan a

When drawing a trend line for a series of data on a scatter plot, which of the following is true? a. there should be an equal number of data points on either side of the trend line. b. all the data points should lie on one side of the trend line. c. the trend line should not intersect any data point on the plot. d. the trend line must connect each data point on the plot.

Compare the subtraction problems 6/8 - 5/8 = 1/8 and 6/9 - 7/9 = 1/9 why is the answer to the first problem positive and the answer to the second problem negative

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys