How to find if two lines are perpendicular?

Iam stuck on one problem. my mind is in absoloute vacation mode. i literallty just need to finish this to be done will give brainliest and all my points if i have to! 1- point free throw and 2- point feild goal. he made 35 shots, and scored 62 points how many of each shot did he make in 1 minute? (i already did the math. he made 8 1-point free throws and 27 2-point feild goals.) 1. write two equations for the problem. (i had a major brain fart.)

What is sin 7x/4 ? i need on this urgent trig

Ill mark the brainliest if you me with the these three questions 7,8,9