All SAT II Math I Resources
Example Questions
Example Question #4 : Ratios And Proportions
If for every inch on a map it represents miles, how many inches will be needed for a distance of miles?
The ratio of inches to miles is
so you can set up a proportion of .
You then cross multiply to get
.
Then you solve for the variable by dividing by which gives us
.
Example Question #37 : Mathematical Relationships
In a geometric sequence the ratio of the first term to the third term is 9:1. What is the ratio of the second term to the fifth term?
Recall that in a geometric sequence there is a constant ratio between any pair of consecutive terms:
If the ratio of the first term to the third term is 9:1 then the ratio of two consecutive terms is a number that when multiplied by itself is 9:
Therefore the common ratio for this sequence is 3.
There are three terms between term 2 and 5 so the common ratio will be applied to the second term three times to get the fifth term:
Since for this sequence
Example Question #1 : Matrices
Define .
Give .
is not defined.
is not defined.
The inverse of a 2 x 2 matrix , if it exists, is the matrix
First, we need to establish that the inverse is defined, which it is if and only if determinant .
Set , and check:
The determinant is equal to 0, so does not have an inverse.
Example Question #2 : Matrices
Give the determinant of the matrix
The determinant of the matrix is
.
Substitute :
Example Question #1 : How To Add Matrices
Simplify:
Matrix addition is very easy! All that you need to do is add each correlative member to each other. Think of it like this:
Now, just simplify:
There is your answer!
Example Question #2 : Matrices
Simplify:
Matrix addition is really easy—don't overthink it! All you need to do is combine the two matrices in a one-to-one manner for each index:
Then, just simplify all of those simple additions and subtractions:
Example Question #1 : Matrices
Evaluate:
This problem involves a scalar multiplication with a matrix. Simply distribute the negative three and multiply this value with every number in the 2 by 3 matrix. The rows and columns will not change.
Example Question #1 : Matrices
Simplify:
Scalar multiplication and addition of matrices are both very easy. Just like regular scalar values, you do multiplication first:
The addition of matrices is very easy. You merely need to add them directly together, correlating the spaces directly.
Example Question #1 : Multiplication Of Matrices
What is ?
You can begin by treating this equation just like it was:
That is, you can divide both sides by :
Now, for scalar multiplication of matrices, you merely need to multiply the scalar by each component:
Then, simplify:
Therefore,
Example Question #1 : Find The Sum Or Difference Of Two Matrices
Given the following matrices, what is the product of and ?
When subtracting matrices, you want to subtract each corresponding cell.
Now solve for and
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