The absolute value of a real number is it's distance from 0 on the number line. Therefore an absolute value must be on the interval [0, oo). If a number is positive then |a|=a and if it is negative then |a|=-a.
Saturday, August 31, 2013
How many zeros does the function g(x) = 4(x + 2)^5 (x-3)^3 + 5(x-3)^4 (x+2)^4 have?
the degree of this polynomial, when expanded is 8, so there are 8 complex solutions.
find the zeros fro g(x), g(x) = 4(x + 2)^5 (x-3)^3 + 5(x-3)^4 (x+2)^4
by grouping
becomes
which simplifies to
so there are 3 unique solutions:
x=-2 (multiplicity 4)
x=3 (multiplicity 3)
x=7/9
becomes
which simplifies to
so there are 3 unique solutions:
x=-2 (multiplicity 4)
x=3 (multiplicity 3)
x=7/9
Thursday, August 29, 2013
I need to know if this problem is identity or contradiction. 4 + 4 (n + 2) = 3n - 2 (n - 5)
4+4(n+2)=3n-2(n-5)
4+4n+8=3n-2n+10
4n+12=n+10
3n=-2
n=-2/3
neither, it is conditional
4+4n+8=3n-2n+10
4n+12=n+10
3n=-2
n=-2/3
neither, it is conditional
Monday, August 26, 2013
If sin A and cos A are the roots of the equation ax^2 - bx + c = 0, then a, b and c satisfy the equation: (A) b^2 - a^2 = 2ac, (B) a^2 - b^2 = 2ac, (C) a^2 + b^2 = c^2 ,(D) a^2 + b^2 = 2ac
A:
The algebra is tedious, but manageable. Use the pythagorean trig identity for sine and cosine set equal to the squares of the 2 roots written in quadratic equation form. Expand and simplify.
The algebra is tedious, but manageable. Use the pythagorean trig identity for sine and cosine set equal to the squares of the 2 roots written in quadratic equation form. Expand and simplify.
find three Consecutive odd Numbers whose sum is 234
Please check your problem statement. The sum of any odd number of odd numbers (in this case three odd numbers) will be odd, so they cannot add to 234 - an even number
Solve: x+y=3, 2y=3x-4
Solving...
1) x+y=3
2) 2y=3x-4
1)...
x=3-y
2)...
2y=3(3-y)-4
2y=9-3y-4
5y=5
y=1
1)...
x=3-1
x=2
1) x+y=3
2) 2y=3x-4
1)...
x=3-y
2)...
2y=3(3-y)-4
2y=9-3y-4
5y=5
y=1
1)...
x=3-1
x=2
Sunday, August 25, 2013
Use the method of substitution to solve the system of linear equations. 2x-y=5, 5x-2y=13
1) 2x-y=5
2) 5x-2y=13
5x-2(2x-5)=13
x=3
y=2(3)-5=1
solution: (3,1)
2) 5x-2y=13
5x-2(2x-5)=13
x=3
y=2(3)-5=1
solution: (3,1)
The length of a rectangle is 4cm more than twice its width. The perimeter is 86cm. Find the width and length.
1) l=4+2w
2) 2(l+w)=86
2) l+w=43
replacing l...
(4+2w)+w=43
3w=39
w=13cm
1) becomes
l=4+2*13
l=30cm
2) 2(l+w)=86
2) l+w=43
replacing l...
(4+2w)+w=43
3w=39
w=13cm
1) becomes
l=4+2*13
l=30cm
Solve: 4m-5n=8, 2m+3n=10
1) 4m-5n=8
2) 2m+3n=10 <-m2
and after we swap their positions...
4m+6n=20
4m-5n=8
then subtract to get
11n=12
n=12/11
from 1)...
4m-5(12/11)=8
4m=8+60/11
4m=148/11
m=37/11
2) 2m+3n=10 <-m2
and after we swap their positions...
4m+6n=20
4m-5n=8
then subtract to get
11n=12
n=12/11
from 1)...
4m-5(12/11)=8
4m=8+60/11
4m=148/11
m=37/11
Saturday, August 24, 2013
Determine which ordered pairs are part of the solution set for each inequality. 2x-3y>6,{(3,2),(-2,-4),(6,2),(5,1)}
Testing points is by substitution:
2(3)-3(2)>6
6-6>6 False
2(-2)-3(-4)>6
-4+12>6 True
2(6)-3(2)>6
12-6>6 False
2(5)-3(1)>6
10-3>6 True
2(3)-3(2)>6
6-6>6 False
2(-2)-3(-4)>6
-4+12>6 True
2(6)-3(2)>6
12-6>6 False
2(5)-3(1)>6
10-3>6 True
Find the real numbers that satisfy the equation: |x| = -1/5
Absolute values are always greater than or equal to 0, so no real number(s) can make this equation true (no solution).
the sum of two numbers is 42. three times the first number is the same as four times the other number. find the number.
1) x+y=42
2) 3x=4y
so...
x=42-y
3x=3(42-y)=4y
3*42-3y=4y
7y=3*42
y=3*42/7
y=18
x=42-18
x=24
2) 3x=4y
so...
x=42-y
3x=3(42-y)=4y
3*42-3y=4y
7y=3*42
y=3*42/7
y=18
x=42-18
x=24
Find x and y intercepts of the graph y=-3
This is a horizontal line so no x-intercept and y-intercept: (0,-3)
Find x and y intercepts of the graph x=-1
This is a vertical line so no y-intercept, x-intercept: (-1,0)
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