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Advanced Math · Exponential And Radical Equations

SAT Exponential And Radical Equations Practice Questions (Free + Explanations) | Quiz 7

Question 12345 of 5

Question 1 of 5

A scientist models the concentration of a chemical in a solution by , where is measured in hours after the start of an experiment. She records the following data.

At what time will the concentration first reach ?

Explanation

From the table,

Dividing the second equation by the first gives

so

Now use to find :

So the model is

Set this equal to :

Divide by :

Therefore, .

Concept summary

Use values from a table to determine the parameters of an exponential function, then solve an exponential equation to find the input that gives a specified output.

Question 2 of 5

A small town had a population of in the year 2000. Since then, the population has been modeled by the equation , where is the number of years after 2000. According to this model, what is the population when ?

Explanation

Substitute into the model:

Since any nonzero number raised to the power equals ,

So the population is .

Concept summary

In an exponential model , when , the value is the initial amount because .

Question 3 of 5

The graph of passes through the point . Which expression is equivalent to this function?

Explanation

Substitute the point into :

So the function becomes .

Concept summary

To find an equivalent form of a radical function with an unknown coefficient, use a given point on the graph and substitute its coordinates to solve for that coefficient while keeping the function's structure the same.

Question 4 of 5

The height, in feet, of a ball seconds after it is dropped is modeled by h=64ig(1-\left(\tfrac{1}{2}\right)^t\big). A sensor is placed so that it turns on when the ball reaches a height of feet. Which statement must be true about the time when the sensor first turns on?

Explanation

Set the height equal to :

Divide by :

So

Therefore, . The statement that must be true is that the sensor first turns on at seconds.

Concept summary

For an exponential equation in context, isolate the exponential expression first, then rewrite both sides with the same base to solve for the variable.

Question 5 of 5

The area of a square is numerically equal to the length of a rectangle. The width of the rectangle is units, and the area of the rectangle is square units. What is the side length of the square, in units?

Explanation

First find the rectangle's length using its area:

The square's area is numerically equal to that length, so the square's area is . If is the side length of the square, then

Since a side length must be positive,

Concept summary

Use the geometric relationship to set up an equation, then solve a simple radical equation such as by taking the positive square root.

Your results

0of 5 correct

Estimated SAT Math band

500-550

Illustrative range from this short quiz—not an official College Board score.

Adaptive practice, weak-area review, and timed tests live in the MCQsLearn app—pick up where you left off on your phone.

More SAT Math practice

Your results

1of 5 correct

Estimated SAT Math band

500-550

Illustrative range from this short quiz—not an official College Board score.

Adaptive practice, weak-area review, and timed tests live in the MCQsLearn app—pick up where you left off on your phone.

More SAT Math practice

Your results

2of 5 correct

Estimated SAT Math band

600-650

Illustrative range from this short quiz—not an official College Board score.

Adaptive practice, weak-area review, and timed tests live in the MCQsLearn app—pick up where you left off on your phone.

More SAT Math practice

Your results

3of 5 correct

Estimated SAT Math band

600-650

Illustrative range from this short quiz—not an official College Board score.

Adaptive practice, weak-area review, and timed tests live in the MCQsLearn app—pick up where you left off on your phone.

More SAT Math practice

Your results

4of 5 correct

Estimated SAT Math band

700+

Illustrative range from this short quiz—not an official College Board score.

Adaptive practice, weak-area review, and timed tests live in the MCQsLearn app—pick up where you left off on your phone.

More SAT Math practice

Your results

5of 5 correct

Estimated SAT Math band

700+

Illustrative range from this short quiz—not an official College Board score.

Adaptive practice, weak-area review, and timed tests live in the MCQsLearn app—pick up where you left off on your phone.

More SAT Math practice