All GRE Subject Test: Math Resources
Example Questions
Example Question #311 : Gre Subject Test: Math
Example Question #11 : Logarithms
Example Question #1 : Logarithmic Properties
Rewrite the following expression as a single logarithm
Recall a few properties of logarithms:
1.When adding logarithms of like base, we multiply the inside.
2.When subtracting logarithms of like base, we divide the inside.
3. When multiplying a logarithm by a number, we can raise the inside to that power.
So we begin with this:
I would start with 3 to simplify the first log.
Next, use rule 1 on the first two logs.
Then, use rule 2 to combine these two.
So our answer is 6.06.
Example Question #131 : Classifying Algebraic Functions
Evaluate:
In order to evaluate the unknown variable, it is necessary to change the base. Looking at the right side of the equation, 27 is equivalent to three cubed.
Therefore, converting the right side of the equation to a base of 3 will allow setting both the left and right side of the exponential terms equal to each other.
Log both sides to drop the exponents by log properties, and divide the log based 3 on both sides to cancel this term.
Solve for x.
Example Question #1 : Change Of Base
Evaluate the following logarithm:
The simplest way to evaluate a logarithm that doesn't have base 10 is with change of base formula:
So we have
Example Question #3 : Change Of Base
In order to solve a logarithm, we must first rewrite it in log form:
To solve for x, we must use the Change of Base:
This means that:
Example Question #1 : Solving Exponential Equations
Find one possible value of , given the following equation:
Cannot be determined from the information given.
We begin with the following:
This can be rewritten as
Recall that if you have two exponents with equal bases, you can simply set the exponents equal to eachother. Do so to get the following:
Solve this to get t.
Example Question #132 : Classifying Algebraic Functions
Solve for .
We need to make the bases equal before attempting to solve for . Since we can rewrite our equation as
Remember: the exponent rule
Now that our bases are equal, we can set the exponents equal to each other and solve for .
Example Question #3 : Solving Exponential Equations
Solve for .
The first step is to make sure we don't have a zero on one side which we can easily take care of:
Now we can take the logarithm of both sides using natural log:
Note: we can apply the Power Rule here
Example Question #4 : Solving Exponential Equations
Solve for .
Before beginning to solve for , we need to have a coefficient of :
Now we can take the natural log of both sides:
Note: