Find the domain of increase of the function:
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Find the domain of increase of the function:
The function given is .
First, let's find the derivative of the function, which will help us determine the intervals of increase.
The derivative is given by .
Next, find where the derivative is zero to locate critical points. Solve to get:
The critical point is . This is where the function changes from decreasing to increasing since quadratic functions have one axis of symmetry and : indicating a parabola opening upwards.
To determine the interval of increase, analyze the sign of :
Thus, the domain of increase for the function is when .
The correct answer is therefore .
Note that the graph of the function shown below does not intersect the x-axis
The parabola's vertex is A
Identify the interval where the function is decreasing:
The derivative tells you the slope at every point! When , the function is going uphill (increasing). When , it's going downhill (decreasing).
A critical point (like ) is where the derivative equals zero. The domain of increase is the entire interval where the function goes up, which is in this case.
Look at the coefficient of ! Since we have and 3 > 0, the parabola opens upward, so it decreases then increases after the vertex.
Yes! For quadratic functions, find the vertex using . Here: . Since a > 0, the function increases for .
Testing the sign tells you the direction of change! Pick any number greater than 1 (like x = 2) and substitute: , confirming the function increases there.
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