Hello I need some help with these 7 questions. If you could please show me all your work on a separate sheet of paper with the solutions/answers that would be great!

1. Find the derivative of f ( x = 5x8 - 3x4 a) first by simplifying the expression and finding the derivative of the simplified polynomial. b) then by using the quotient rule. 2. Find the derivative of f ( x ) = 3x2 -4x 2x+ 1 3. Find the derivative for 8 (x ) = x 2 + 1 3.x4- 2x3 4. Find the derivative for k ( x ) = x3 x2+9 5. Find the derivative for m (x ) = - et COs * 6. The radius of a circular juice blot on a piece of paper towel t seconds after it was first seen is modelled by the function r(1) = 1+21 1+ t where r is measured in centimetres. Calculate a) the radius of the blot when it was first observed. b) the time at which the radius of the blot was 1.5 cm c) the rate of increase of the radius of the blot when the radius was 1.5 cm. 7. The concentration, c, of a drug in the blood t hours after the drug is ingested is given by the formula c (t) = 212+7 When does the concentration reach it's maximum (peak) value ? (Hint - what is the value of the slope of the tangent line at a "peak" on a curve ? )