4. A small balloon is released at a point 150 feet away from an observer who is on level ground. If the balloon goes straight up at the rate of 8 feet per second, how fast is the distance from the observer to the balloon increasing when the balloon is 50 feet high? 5. Evaluate the following anti-derivatives: using the Substitution Method a) Jein 2x cos 2x dx b) Inx Inx dx X COS X c) S -dx d) s. e) s. sin x + 2 1 √√3x+1 dx 2x+3 √x* +3x+1 f) fe2x+5 dx g) (. 2x+3 x²+3x+2 -dx dx