Warm-Up: A. The height, in metres, of a golf ball seconds after Billy Bob hits it with a club is h, t described by = -5t2 + 30t. How long is the ball in the air? h B. The height, in metres, of a football seconds after Billy Bob throws it off the roof of h, t a building is described by = -5t2 + 20t + 25. How long is the ball in the air? h C. The height, in metres, of a baseball seconds after Billy Bob hits it with a bat is h, t described by = -5t2 + 18t+1. For how long is the ball in the air? h To find the zeros of ax2 + bx + c = 0, you can use this Quadratic Formula: a = ________ b = ________ c = ________ Example B from above: substitute the values of a, b, and c into the formula (use brackets!) use your calculator to determine the value under the square root sign take the square root (round to 1 decimal if required) split the equation into 2 equations one with the or – and one with the ‘+’ ‘–’ or calculate the numerators = ________ or = ________ divide to get your zeros t t Discriminant
Warm-Up: A. The height, h, in metres, of a golf ball t seconds after Billy Bob hits it with a club is described by h = -5t2 + 30t. How long is the ball in the air? B. The height, h, in metres, of a football t seconds after Billy Bob throws it off the roof of a building is described by h = -5t2 + 20t + 25. How long is the ball in the air? C. The height, h, in metres, of a baseball t seconds after Billy Bob hits it with a bat is described by h = -5t2 + 18t+1. For how long is the ball in the air? To find the zeros of ax2 + bx + c = 0, you can use this Quadratic Formula: Example B from above: a = ________ b = ________ c = ________ substitute the values of a, b, and c into the formula (use brackets!) use your calculator to determine the value under the square root sign take the square root (round to 1 decimal if required) split the equation into 2 equations – one with the ‘+’ and one with the ‘–’ or calculate the numerators or divide to get your zeros t = ________ or t = ________ Discriminant
5_-_solving_quadratic_equations_by_using_the_formula_handout.docx