Square Root Functions, algebra homework help

Writing in Math Refer to the information on 

page 397

 to explain how square root functions can be used in bridge design. Assess the weights for which a diameter less than 1 is reasonable. Evaluate the amount of weight that the Sunshine Skyway Bridge can support.

7-3
Square Root Functions
and Inequalities
GET READY for the Lesson
Main Ideas
• Graph and analyze
square root functions.
• Graph square root
inequalities.
The Sunshine Skyway Bridge
across Tampa Bay, Florida, is
supported by 21 steel cables, each
9 inches in diameter. The amount
of weight that a steel cable can
support is given by w = 8d2,
where d is the diameter of the
cable in inches and w is the
weight in tons.
New Vocabulary
square root function
square root inequality
If you need to know what
diameter a steel cable should
have to support a given weight,
you can use the equation
d = V
Square Root Functions If a function contains a square root of a variable,
it is called a square root function. The parent function of the family of
square root functions is y = Vx. The inverse of a atic function is a
square root function only if the range is restricted to nonnegative
numbers.
у
y = x2
y = x2
0
= +Vx
y = +Vx is not a function.
y = VX is a function.
In order for a square root to be a real number, the radicand cannot be
negative. When graphing a square root function, determine when the
radicand would be negative and exclude those values from the domain.
Lesson 7-3 Square Root Functions and Inequalities 397
Raymond Gehman/CORBIS