a man is now 9 times as old as his daughter. in four years time he'll be five times as old as his daughter. what are their prese
1 answer:
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Answer:
Option (2). Increasing x > 0; decreasing x < 0
Step-by-step explanation:
Equation of the parabola having vertex (0, 3) will be,
y = (x - 0)² + 3
y = x² + 3
To check the function is increasing or decreasing in the given intervals we will find the derivative of the function,
y' = 2x
For x < 0 Or x = -1
y' = 2(-1)
= -2 < 0
Therefore, function is decreasing in x < 0
For x > 0 Or x = 1
y' = 2(1) + 3
= 5 > 0
Therefore, function is increasing in x > 0
Option (2) is the answer.