First one: If the leading coeff. is negative, the graph begins in Quadrant III and ends in Quadrant IV. It's an even function. The fourth graph represents it.
If the leading coeff. is positive, but everything else remains the same, the graph opens upward, beginning in Q II and ending in Q I.
Since it forms a "right triangle" we can apply trigonometry.
sin x = oppo/hyp
sin x = 13/20
x = sin^-1(13/20)
x = sin^-1(0.65)
x = 40.5
rounded to nearest degree
x = 41 degrees
Hope this helps! :)
From least to Greatest: 8/100, 7/10, 3/5
