Question

A formula for the normal systolic blood pressure for a man age A, measured in mmHg, is given as P=0.006A2−0.02A+120. Find the age of a man whose normal blood pressure measures 126 mmHg.

Round your answer to the nearest year.

Answer 1

33 years

Explanation:

Given the quadratic model :

P=0.006A2−0.02A+120

P = blood pressure ; A = Age

Given a blood pressure value of 126 mmHg ; the age, A will be ;

The equation becomes :

126 = 0.006A2−0.02A+120

0.006A² - 0.02A + 120 - 126 = 0

0.006A² - 0.02A - 6 = 0

Using the quadratic formula :

-b ± (√b²-4ac) / 2a

a = 0.006 ; b = - 0.02 ; c = - 6

Using calculator :

The roots are :

a = 33.333 or a = - 30

Age cannot be negative, hence, the age, A will be 33.333

Total the nearest year ; Age = 33 years