which is a trinomial with a leading coefficient of 2 a) 2x^4 +3x -sqrt(x) b) 2x^4 + sqrt(3)x +1
Trinomial - polynomial with 3 terms
Polynomials don't contains roots of x (only whole number powers). (rather they are defined for all x, including negative x values)
However, a polymial CAN have an irrational coefficient in one of the terms.
Ohhh so it would be B then
Yes
Also -- a polynomial can have all terms with irrational coefficients ... I said 1 irrational coefficient because that is the case in your example...
(but not to restrict the polynomial to only 1 irrational coefficient)
Okay thanks! can you help me with another problem?
Yes \( : ) \)
Factor completely [4x(x+1)^1/2+ 3(x+1)^-1/2] / (x+1)^1/2
\(\large\color{#000000 }{ \displaystyle \frac{4x(x+1)^{1/2}+3(x+1)^{-1/2}}{(x+1)^{1/2}} }\) this is how you wrote it, and I just want to verify that this is indeed the equations.
equation **
yes that's is
What I would do, is to multiply times \((x+1)^{1/2}\) on top and bottom.
Not that; \((x+1)^{1/2} \times (x+1)^{1/2} = (x+1)^{1/2+1/2}=(x+1)^1=x+1\) and \((x+1)^{1/2} \times (x+1)^{-1/2} = (x+1)^{1/2+-1/2}=(x+1)^0=1\)
okay so the denominator is equal to x+1
so (after multiplying times \((x+1)^{1/2}\) on top and bottom), you get the following equation: \(\large\color{#000000 }{ \displaystyle \frac{\color{red}{\left\{\color{black}{4x(x+1)^{1/2}+3(x+1)^{-1/2}}\right\}\times (x+1)^{1/2}}}{(x+1)^{1/2}\color{red}{\times (x+1)^{1/2}}} }\) you got the denominator (correctly) \(\large\color{#000000 }{ \displaystyle \frac{\color{red}{\left\{\color{black}{4x(x+1)^{1/2}+3(x+1)^{-1/2}}\right\}\times (x+1)^{1/2}}}{x+1} }\)
\(\large\color{#000000 }{ \displaystyle \frac{\color{red}{\left\{\color{black}{4x(x+1)^{1/2}+3(x+1)^{-1/2}}\right\}\times (x+1)^{1/2}}}{x+1} }\) expanding; \(\large\color{#000000 }{ \displaystyle \frac{\color{red}{\left\{\color{black}{4x(x+1)^{1/2}}\right\}\times (x+1)^{1/2}}+\color{red}{\left\{\color{black}{3(x+1)^{-1/2}}\right\}\times (x+1)^{1/2}}}{x+1} }\)
REMINDER \((x+1)^{1/2} \times (x+1)^{1/2} = (x+1)^{1/2+1/2}=(x+1)^1=x+1\) and \((x+1)^{1/2} \times (x+1)^{-1/2} = (x+1)^{1/2+-1/2}=(x+1)^0=1\)
okay so it = 4x(x+1)+3?
Yes the numerator is 4x(x+1)+3 , correct!
\(\large\color{#000000 }{ \displaystyle \frac{4x(x+1)+3}{x+1} }\)
Yay! thank you so much @SolomonZelman :)
but, the instructions say "factor", and I am not sure whteher I fullfilled the instructions (althouhg we certainly simplified it).
yes one of the answer choices is (4x^2 +4x+3)/x+1
Oh, I guess they don't know what the word factor means, but even better to us - we can move on away from this problem.
Do you have any questions regarding anything what we have done here (or anything (math-related) you have done elsewhere)?
Hmm well im also doing some log problems and they always confuse me
Sure :)
You can ask me now if you want...
Okay thanks I will tag you in a new post with another question. You are extremely helpful!
Some good properties (whether related to what you are doing or not, but they are crucial for the rest of your mathematical life)... Product inside the log, \(\large \color{#000000 }{ [1]\quad \displaystyle \log_{\color{red}{\rm A}}(\color{green}{\rm B}\times \color{blue}{\rm C})=\log_{\color{red}{\rm A}}(\color{green}{\rm B})+\log_{\color{red}{\rm A}}( \color{blue}{\rm C}) }\) Quotient inside the log, \(\large \color{#000000 }{ [2] \quad \displaystyle \log_{\color{red}{\rm A}}(\color{green}{\rm B}\div \color{blue}{\rm C})=\log_{\color{red}{\rm A}}(\color{green}{\rm B})-\log_{\color{red}{\rm A}}( \color{blue}{\rm C}) }\)
Exponent inside the log, \(\large \color{#000000 }{ [3]\quad \displaystyle \log_{\color{red}{\rm A}}(\color{green}{\rm B}^\color{purple}{\bf C})=\color{purple}{\bf C}\cdot \log_{\color{red}{\rm A}}(\color{green}{\rm B}) }\)
Changing the base of log, \(\large \color{#000000 }{ [4]\quad \displaystyle \log_{\color{red}{\rm A}}(\color{green}{\rm B})=\frac{\log_\color{magenta}{\bf W}(\color{green}{\rm B})}{\log_\color{magenta}{\bf W}(\color{red}{\rm A})} }\) You can substitute any (positive) base \(\color{magenta}{\bf W}\) using this formula.
(As I am posting some properties of logarithms you can post any question if you want)
For as much as I am aware of, this is it.
One more, one of my famous properties; \(\large \color{#000000 }{ [5]\quad \displaystyle {\color{red}{\rm A}}^{\Large \log_{\color{red}{\rm A}}(\color{green}{\rm x})}=\color{green}{\rm x} }\) I always use this as; \(\Large \color{#000000 }{ \displaystyle e^{\ln(\color{green}{\rm x})}= {\color{red}{\rm e}}^{\Large \log_{\color{red}{\rm e}}(\color{green}{\rm x})}=\color{green}{\rm x} }\)
if you got questions, don't hesitate; you know --:)
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