MHB What are the values of x for f(x) = g(x)?

  • Thread starter Thread starter Iwanttolearn1
  • Start date Start date
Iwanttolearn1
Messages
3
Reaction score
0
Hello, mathhelpboards. I'm having trouble solving this problem on my review but can't figure out how to start it.

Find the values of x for which f(x) = g(x).

f(x) = x^2 , g(x) = 10 - 3x.

It seems like its easy but I can't really pick out what to put what where.
 
Mathematics news on Phys.org
Iwanttolearn said:
Hello, mathhelpboards. I'm having trouble solving this problem on my review but can't figure out how to start it.

Find the values of x for which f(x) = g(x).

f(x) = x^2 , g(x) = 10 - 3x.

It seems like its easy but I can't really pick out what to put what where.

Hey Iwanttolearn! Welcome to MHB! ;)

Let's see...
\[
f(x)=g(x) \Rightarrow x^2=10-3x \Rightarrow x^2+3x-10=0
\]
For which $x$ would that be the case? (Wondering)
 
I like Serena said:
Hey Iwanttolearn! Welcome to MHB! ;)

Let's see...
\[
f(x)=g(x) \Rightarrow x^2=10-3x \Rightarrow x^2+3x-10=0
\]
For which $x$ would that be the case? (Wondering)

So you would put the f(x) value into the g(x)? I think that looks right or either I'm completely wrong.
 
Iwanttolearn said:
So you would put the f(x) value into the g(x)? I think that looks right or either I'm completely wrong.

We're replacing the occurences of $f(x)$ and $g(x)$ by their respective definitions.
That gives us an equation we can solve with the quadratic formula, or just with inspection...
 
I like Serena said:
We're replacing the occurences of $f(x)$ and $g(x)$ by their respective definitions.
That gives us an equation we can solve with the quadratic formula, or just with inspection...

Oh wow! I get it now. Many thanks your way!(Handshake)(Happy)
 

Thread 'What Exactly is Dirac’s Delta Function? - Insight'

Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
View full post »

Thread 'Fermat's Last Theorem'

Fermat's Last Theorem has long been one of the most famous mathematical problems, and is now one of the most famous theorems. It simply states that the equation $$ a^n+b^n=c^n $$ has no solutions with positive integers if ##n>2.## It was named after Pierre de Fermat (1607-1665). The problem itself stems from the book Arithmetica by Diophantus of Alexandria. It gained popularity because Fermat noted in his copy "Cubum autem in duos cubos, aut quadratoquadratum in duos quadratoquadratos, et...
View full post »
Thread 'Imaginary Pythagorus'

Thread 'Imaginary Pythagorus'

I posted this in the Lame Math thread, but it's got me thinking. Is there any validity to this? Or is it really just a mathematical trick? Naively, I see that i2 + plus 12 does equal zero2. But does this have a meaning? I know one can treat the imaginary number line as just another axis like the reals, but does that mean this does represent a triangle in the complex plane with a hypotenuse of length zero? Ibix offered a rendering of the diagram using what I assume is matrix* notation...
View full post »

Similar threads

MHB Proving Equivalence of f(x) and g(x)
Replies
2
Views
1K
MHB Solving g(x)-h(x) <0: Find a, b, c, d
Replies
2
Views
1K
MHB What is the Result of Plugging g(x) Into f(x)?
Replies
4
Views
2K
MHB Max Value of $b$ for Real Roots of $f(x)$ and $g(x)$
Replies
2
Views
1K
MHB If f(3x) = f(3) + f(x) , then prove that : f(1) = f(3) =f(9) = f(27) = f(81) = 0
Replies
6
Views
2K
B Irrational inequalities √f(x)>g(x) and √f(x)>g(x)
Replies
7
Views
2K
MHB F(x) = x2-7 and g(x) = x- 3, find (f º g )(x) [2]
Replies
3
Views
2K
MHB If g(x) =(kx-p)/(2) , g(7) = 8 , g(5) = 5 then find the value of x and g(x)
Replies
2
Views
1K
MHB Solving 8 Roots: Can 3 Quadratic Polynomials Fulfill $f(g(h(x)))=0$?
Replies
1
Views
1K
MHB Find the roots of f(x)+g(x)+h(x) = 0.
Replies
2
Views
2K

Hot Threads

Recent Insights

Back
Top