Answer: Choice A
g(x) = sqrt(2x)
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Explanation:
"sqrt(x)" is shorthand for "square root of x"
f(x) = 3x^2 is given
g( f(x) ) = x*sqrt(6) is also given
One way to find the answer is through trial and error. This would only apply of course if we're given a list of multiple choice answers.
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Let's start with choice A
g(x) = sqrt(2x)
g( f(x) ) = sqrt(2 * f(x) ) .... replace every x with f(x)
g( f(x) ) = sqrt(2 * 3x^2 ) .... plug in f(x) = 3x^2
g( f(x) ) = sqrt(6x^2 )
g( f(x) ) = sqrt(x^2 * 6)
g( f(x) ) = sqrt(x^2)*sqrt(6)
g( f(x) ) = x*sqrt(6)
We found the answer on the first try. So we don't need to check the others.
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But let's try choice B to see one where it doesn't work out
g(x) = sqrt(x + 3)
g( f(x) ) = sqrt( f(x) + 3)
g( f(x) ) = sqrt(3x^2 + 3)
and we can't go any further other than maybe to factor 3x^2+3 into 3(x^2+1), but that doesn't help things much to be able to break up the root into anything useful. We can graph y = x*sqrt(6) and y = sqrt(3x^2 + 3) to see they are two different curves, so there's no way they are equivalent expressions.
the domain:
the equation:
4 is in the domain
-2 is not in the domain
The answer:
***
Also, the answer in 13 is {8}. -3 is not in the domain. Replace x with -3 and you'll see:
It's not true so -3 isn't a solution to this equation.
Answer:
B' will be at (0, -3)
Step-by-step explanation:
if A is (5, 1), and A' is (6, -2) that means that the value of x increased by 1 and y decreased by three. Because translations are uniform, you apply this to B, getting (0, -3)
Answer:
x = 4 + sqrt(73) or x = 4 - sqrt(73)
Step-by-step explanation by completing the square:
Solve for x:
(x - 12) (x + 4) = 9
Expand out terms of the left hand side:
x^2 - 8 x - 48 = 9
Add 48 to both sides:
x^2 - 8 x = 57
Add 16 to both sides:
x^2 - 8 x + 16 = 73
Write the left hand side as a square:
(x - 4)^2 = 73
Take the square root of both sides:
x - 4 = sqrt(73) or x - 4 = -sqrt(73)
Add 4 to both sides:
x = 4 + sqrt(73) or x - 4 = -sqrt(73)
Add 4 to both sides:
Answer: x = 4 + sqrt(73) or x = 4 - sqrt(73)
23x25 is the same as 46x50 because you just multiplied both by two
