Which quadrant of the coordinate plane has ordered pairs in the form of a positive number and a negative number, (+,-)?

If c(x) = 4x – 2 and d(x) = x2 + 5x, what is (cxd)(x)

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.