Determining the End Behavior of a Polynomial Function HELP ASAP

According to the normal model, what percent of receivers would you expect to gain fewer yards than 2 standard deviations below the mean number of yards

Daniel expanded the expression as shown below -2(-8x-4y+3/4)=-10x-8y-11/4 what errors did he make? check all that apply

Which of the following functions corresponds to the above sinusoid? a. 10 cos πx - 5 b. -5 sin x - 5 c. -10 cos πx/2 - 0.5 d. 10 sin πx - 5