Calculus
posted by Elisabeth .
Is x^2  2x
1 to 1?
I keep getting yes every way I try to work it. Book says no. In the end, I get (with x1=1 and x2=1 < I use these numbers because of the x^2) f(x1) = 1 and f(x2)=3. I can't seem to find if x1 = x2
(btw, I know that by the graph it is not, but I am trying to work it out the books way)

I should add that my prof said in the notes that if the two answers to the two functions are the same, then it is not 1 to 1 BECAUSE they have the same answer. That's what has me confused.

Onetoone is usually associated with an interval. If the interval is not mentioned, we will assume that it is (∞∞).
To find out if a function
f(x) is onetoone on the interval, we need to know if it is possible to find different values of x1 and x2 for which f(x1)=f(x2), where x1x2≠0.
If f(x1)=f(x2) then f(x) is not onetoone on the given interval.
For example,
f(x)=x² on the interval (∞,∞),
we can find
f(1)=f(1), or f(2)=f(2), therefore f(x)=x² is NOT onetoone.
The horizontal line test says that if you can draw a horizontal line and intersect the function at two or more points, the function is NOT onetoone. On the other hand, if it is impossible to do so, the function is onetoone.
Try out your problem and post if you have other questions.
Respond to this Question
Similar Questions

help C program
I keep getting an error that says "no new endline at the end of file" but i pressed enter and it still won't work. i am compiling with gcc are there anything else i should look at? 
Probability
Find the probablity of getting a sum of at least 8 by tossing a sixsided die twice. I keep getting 5/36 but my book says 5/12. 
Math
I can't figure out 6  2/3r = 1 1/2 The way we're learning how to solve it, is by using the LCD. the LCD I use is 6 The book says the answer is 6 3/4 But I keep getting the wrong answer. 
Math
5 = 1/2 (x6) I keep getting 8 as my answer, but the book says it's 16? 
6th grade math
Find the value fir each expression. Show your work. (13.28  7.8) divided by 4. I have the answer in the back of my book and when I try to work the problem out I keep getting the wrong answer. The answer is supposed to be 1.345 I can … 
algebra
f(x)= 1/x2 Plug in 1 for x. I keep getting 1 but the book says the answer is 3. Please help. Thanks 
Calculus
Use implicit differentiation to find dy/dx. e^4x = sin(x+2y). This is a practice problem. It says the correct answer is 4e^x/(2sin(x+2y)) but I keep getting 4e^(4x)/(2cos(x+2y)). I thought the derivative of e^(4x) would be 4e^(4x), … 
Algebra 1
Which statement about real numbers is true? 
physics
Suzanne bikes 3 km to school every day. It takes her 20 minutes because she always has to stop at a traffic light. What is her average speed? 
8th Grade Mathexponents
Let me try writing it again... (X/2)^3*(X/2)^4  (X/2^3)^2 I keep getting X/2^6, but the book says X/2^5. How do you get X/2^5?