Rachel would take 30 minutes to run in 4miles
Answer:
Option B (35°).
Step-by-step explanation:
To solve this question, the trigonometric identity sin x = cos (90-x) is required. It can also be written as cos x = sin (90-x). It can be seen that this identity holds when the two angles are complementary i.e. they sum up to 90 degrees. Therefore, the answer can be determined by substituting all the options one by one in the identity cos x = sin (20+x). If x=30 degrees, then x+20=50 degrees. 30 and 50 are not complementary. If x=35 degrees, then x+20=55 degrees. 35 and 55 are complementary since their sum is 90 degrees. Therefore, B is the correct choice!!!
Answer: = −9
Step-by-step explanation:
The path is in the shape of a parabola, the horizontal length is 24, so the middle point is at x=12, the symmetry line is x=12, the highest point (the vertex) is at (12,6)
the equation in vertex form is y=a(x-12)²+6
next, find a by using either one of the two points, the starting point (0,0) or the end point (0,24). obviously (0,0) is easier to calculate:
0=a(0-12)² +6
a=-1/24
so the quadratic equation is y=-