What graph correctly solves the system of equations below?
y = −x2 − 1; y = 2x2 − 4.
Quadratic equations are equations with degrees equal to two. They can have at most two roots. A system of two quadratic equations can have at most two solutions, that is, the points where they intersect.
Answer: The solution to the system of equations given y = −x2 − 1; y = 2x2 − 4, is (-1, -2) and (1, -2).
Let's understand the solution in detail.
Explanation:
Given system of equations:
⇒ y = −x2 − 1
⇒ y = 2x2 − 4
Now, we equate both the equations given since both of them are equal to y.
⇒ −x2 − 1 = 2x2 − 4
⇒ 3x2 - 3 = 0
Solving the above equation for x, we get:
⇒ x = 1 or x = -1
Now, we find the corresponding values of y, using either of the equations: y = -(-1)2 - 1 = -2 or y = -(1)2 - 1 = -2
We get the solutions (-1, -2) and (1, -2).
Now, we plot the system of equations in the graph as shown below.
From the graph, we can clearly see that both the curves intersect at the point (-1, -2) and (1, -2) which are the solutions to the system of equations given.
Hence, the solution to the system of equations given is (-1, -2) and (1, -2).
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