All GRE Subject Test: Math Resources
Example Questions
Example Question #181 : Algebra
Which of the following is the inverse of ?
Which of the following is the inverse of ?
To find the inverse of a function, we need to swap x and y, and then rearrange to solve for y. The inverse of a function is basically the function we get if we swap the x and y coordinates for every point on the original function.
So, to begin, we can replace the h(x) with y.
Next, swap x and y
Now, we need to get y all by itself; we can to begin by dividng the three over.
Now, recall that
And that we can rewrite any log as an exponent as follows:
So with that in mind, we can rearrange our function to get y by itself:
Becomes our final answer:
Example Question #12 : Linear Algebra
Find the Inverse of Matrix B where
.
To find the inverse matrix of B use the following formula,
.
Since the matrix B is given as,
the inverse becomes,
.
Example Question #11 : Inverses
Find the inverse of the following matrix, if possible.
The inverse does not exist.
Write the formula to find the inverse of a matrix.
Substituting in the given matrix we are able to find the inverse matrix.
Example Question #1 : Determinants
Given the following matrix, find the determinant, if possible.
There is no determinant.
Write the formula to find the determinant given a 2 by 2 matrix.
Substituting in the given matrix we are able to find the determinant.
Example Question #2 : Determinants
Evaluate the determinant of the following matrix.
Remember, to evaluate the determinant of a matrix use the following:
The first step would be to write the determinant of the matrix:
Now we can evaluate:
Example Question #3 : Determinants
Evaluate the determinant of the following matrix.
To find the determinant of a 3 x 3 matrix, we must use the following:
The first thing we must do is write the determinant:
Now we can proceed to evaluate the determinant
Notice that the numbers 2, 4, and 3 are being multiplied by the determinants of the 2x2 matrices so we have:
Example Question #193 : Algebra
Find the determinant of the matrix:
Step 1: We need to recall how to find the determinant of a matrix. To find the determinant of a matrix, we need to use the equation , where =Determinant, and are from the matrix.
Step 2: Identify a,b,c, and d in the original matrix.
a=first number on top row, b=second number on top row (next to a), c=first number on the bottom row, and d is the second number on the bottom row (next to c).
In this matrix, a=, b=, c=, and d=.
Step 3: Substitute the values of a,b,c, and d into the equation to find the determinant of the matrix.
We will simplify the right side.
. We see that there are two negative signs in the middle, which will become a plus sign.
. Simplify the right side.
. is the determinant.
The determinant of the matrix is .
Example Question #2 : Determinants
Find the determinate of Matrix A.
Matrix A is given below.
The formula for the determinate of a 2x2 matrix is:
Plugging in the values gives us:
Example Question #1 : Vectors
Calculate the dot product of the following vectors:
Write the formula for dot product given and .
Substitute the values of the vectors to determine the dot product.
Example Question #1 : Vector Form
Express in vector form.
The correct form of x,y, and z of a vector is represented in the order of i, j, and k, respectively. The coefficients of i,j, and k are used to write the vector form.
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