Posted by Untamed on Thursday, November 24, 2011 at 9:14pm.
Find the Zeros of the following functions
f(x) = x/3 +5
^ That one is layed out so differently I don't understand how to solve.
In each of the following, determine the zeros of the function and determine the yintercept of the graph of the function.
f(x) = 5x^2  35x
f(x) = 3x(x^249)

Math  Steve, Friday, November 25, 2011 at 12:05am
It's not so different. It just has a fraction. You can always use y instead of f(x)
y = x/3 + 5
To solve, set y=0 and solve for x
0 = x/3 + 5
x/3 = 5
x = 3/5
___________________
The yintercept is always easy. Just plug in x=0 and evaluate y
y = 5x^2  35x
y(0) = 0 so the yintercept is (0,0)
5x^2  35x
= 5x(x7)
so, y=0 when
5x(x7) = 0
x=0 or x=7
The xintercepts are (0,0) and (7,0)
Note that (0,0) is both an xintercept and a yintercept.
_______________________
y = 3x(x^2  49)
Think back to your factoring exercises, and recall the difference of two squares:
(a+b)(ab) = a^2  b^2
y = 3x(x+7)(x7)
So, the yintercept is (0,0)
xintercepts are (0,0) (7,0) and (7,0)
Answer This Question
Related Questions
 calculus  For the following function f(x)=2x^46x^2+2x1. Find the maximum ...
 Maths  I have a test tomorrow and I really don't get this, please help me. "Use...
 advanced functions/precalculus  1. The function f(x) = (2x + 3)^7 is the ...
 college allgebra  f(x)=x^6+4x^5+4x^4+3x^3x^25x+4 Find the maximum number of ...
 Decartes Rule of Signs  Could you explain to me decartes Rule of signs? Here ...
 Algebra 2  One of the the zeros of the functions F(x)= x^4+2x^313x^238x24 is...
 college algebra  1. solve the following logarithmic equation log_8(x+8)+log_8(x...
 Math  I just wanted to double check that I am correct. 1.Find the zeros for the...
 alg 2  find all zeros of the following function: f(x)=x^3x^2+4x4 I have (x^2+...
 algebra  p(x)=x^3+2x^23x+20 one of this functions zeros is 4 When using ...
More Related Questions