Find all points, if any, where y - 4x = 12 intersects 2 - y = 2(x + 2)2
Solution:
It is given that,
y - 4x = 12 intersects 2 - y = 2(x + 2)2,
Now, consider y - 4x = 12, this can also be written as below,
y = 4x + 12 … [equation 1]
Also consider the other equation,
2 - y = 2(x + 2)2 this can also be written as below,
2 - 2(x+2)2 = y … [equation 2]
We have both the y's isolated.
We consider, as stated earlier, that in order to intersect, the equations have equal x values and equal y values.
So we know that y = y and x = x.
Since y = y, we can say that both equations contain sides opposite y that are equal.
Then,
4x + 12 = 2 - 2(x + 2)2
Now we have to solve for x,
We know that, (a + b)2 = a2 + 2ab + b2
4x + 12 = 2 - 2(x2 + (2 × x × 2) + 22)
4x + 12 = 2 - 2(x2 + 4x + 4)
4x + 12 = 2 -2x2 - 8x - 8
By transposing we get,
2x2 + 8x + 4x + 12 + 6 = 0
2x2 + 12x + 18 = 0
By taking common terms outside, we get
2(x2 + 6x + 9) = 0
2(x + 3)2 = 0
(x + 3)2 = 0/2
x + 3 = √0
x = -3
Now we have to substitute the value of x in equation 1 to get y,
y = 4(-3) + 12
y = -12 + 12
y = 0
Therefore, x = - 3 and y = 0 are the points where y - 4x = 12 intersects 2 - y = 2(x + 2)2.
Find all points, if any, where y - 4x = 12 intersects 2 - y = 2(x + 2)2
Summary:
x = - 3 and y = 0 are the points where y - 4x = 12 intersects 2 - y = 2(x + 2)2.
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