Mid-term Flashcards
When deviding multipule devisions e.q 5/ 1/2 what should you do?
We first devide the denominator 1/2 which gives us 0.5 and then we divide 5/0.5 which gives us 10
If a question asks you at what the graph crosses the x-axis at? You should answer in what form.
(x, y)
When asked to answer a question about the x-intercept or y-intercept you should answe in the form OR a question about using the graphs of f and g to find (f + g)(0 or any other number)
The x or y NOT (x,y)
For the second question: we answer in this form but we also add the answer of f + g. If we was going to find find (f - g)(0 or any other number) we was going to subtract f - g
A rule to remember always when substituting is
To always susitute to the right
Slope-intercept
y=mx+b
Point_slope intercept
y-y = m(x-x)
When finding the avarage rate of an equation such as f(x)=x^2 - x + 4 what formula to use and how to solve it?
The formula is f(x^2) - f(x^1)/ x^2 - x^1
To solve it we use the equation (which in this case is f(x)=x^2 - x + 4) and then we solve for f(x^2) and then f(x^1) which will look like this: f(6) - f(2) / 6 - 2 = 34-6/4 = 28/4 = 7
How to write the following= The y-value is four less than four times the x-value. AND The y-value is five incrfeased by the square of the x-value.
First equation: y= 4 - 4X or y = 4x - 4
Second: y=5+x^2 or y=x^2 + 5
The NOTATION f o g called the ….. and is defined as ……
The compositionof the function f with g and is defined as f(g(x))
What to do when finding a fuction domain such as 7/x^2 - 25?
Since the denominator x^2 - 25 should not be 0 we look for the numbers that make the denominator 0 which are in this case **-5 and 5 ** (remeber to always include the negative one with an x^2 equation)
Find the domain of the function 1/square root of x-1
(1, infinity sign) and NOT [1, infinity sign) We use the [ Only if it was not in the denominator
Find the domain of the function square root 25 - 5x
(- infinity, 5]
Always when the x (in this case 5x) is negative we change the sign > to <
Find the domain of the function square root x -11 + square root x + 1
since square root x -11 will be [11, infinity) and square root x + 1 will be [-1, infinity) Our ANSWER will be [11, infinity) because it is bigger than [-1, infinity)
Find the domain of the function square root x - 2 / x - 6
The answer will be [2,6) U (6, infinity) WHY? because the numerator contain the square root of x-2 and its answer is [2, infinty)
How would you answer a question with (fg)(x) and a question with f o g
(fg)(x) means f(x) multiply by g(x) while f o g means f(g(x))