## Precalculus Practice Exam

Part 3 Test 3 Time: 1 hour

• Write the expression

as one simplified " " term.

• Determine the domain that makes the original expression equivalent to the final expression.

Answer: The domain that makes both equations to be equivalent is x>6, or in interval notation, .

1. Solve the following equation for x:

• Solve the following equation for x:

• What is the common domain of the two functions?

Answer: The common domain of the two functions is 6<x<8, or in interval notation, (6,8).

2. The half-life of Ra is 1,620 years. How long before the sample reduces to 67% of the original amount?

Answer: It will take 936 years.

3. Find the special parabola that contains the points (3,26), (-2,21), and (1,6).

Answer: The parameters of the parabola are a=3,b=-2,c=5, so the equation for the parabola is

• Find the inverse of the function

• Give the domain and range for f(x) and .

Answer: The domain of f(x) is x>2, or in interval notation, .
The range of f(x) is all real numbers, or in interval notation, .

The domain of is all real numbers, or in interval notation, .
The range of is y>2, or in interval notation, .

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Sun Jun 22 21:16:15 MDT 1997