D is directly proportional to the square of t d=80 when t=4 so d=kt^2 k being the constant k=80/64 Work out the positive value of t when d=45 Can this be equated accurately without a calculator?
Follow Math Help Forum on Facebook and Google+
Originally Posted by Mukilab D is directly proportional to the square of t d=80 when t=4 so d=kt^2 k being the constant k=80/64 WRONG!! 4^2 = 16, NOT 64 Work out the positive value of t when d=45 Can this be equated accurately without a calculator? D is directly proportional to the square of t does mean: $\displaystyle d=k . t^{2}$ d=80 when t=4 gives you: $\displaystyle 80 = k \times (4)^2 \implies k = \frac{80}{16}=5$ Now can you find t when d=45?
View Tag Cloud