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blackpanther
Username
blackpanther
Score
473
Membership
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Questions
124
Answers
1
124 Questions
1 Answers
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+473
floor
Find the number of positive integers ${}n$ that satisfy $\lfloor \sqrt{n} \rfloor + \lfloor \sqrt{4n} \rfloor = 5.$
blackpanther
1 hour ago
0
1
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+473
hard sum
Let
\[f(x) = \left\lfloor\frac{2 - 3x}{2x + 8}\right\rfloor.\]
Evaluate $f(1)+f(2) + f(3) + \dots + f(999)+f(1000).$ (This sum has $1000$ terms, one for the result when we input each integer from $1$ to $1000$ into ${}f$.)
blackpanther
1 hour ago
0
1
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+473
help trig
In right triangle $BCD$ with $\angle D = 90^\circ$, we have $BC = 10$ and $BD = 8$. Find $\sin B$.
blackpanther
1 hour ago
0
1
1
+473
coordinates
Find all points $(x,y)$ that are $5$ units away from the point $(2,7)$ and that lie on the line $y = 5x - 28.$
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blackpanther
Dec 9, 2023
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+473
Counting
Find the number of positive integers that satisfy both the following conditions:
- Each digit is a 1 or a 3 or a 5
- The sum of the digits is 6
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blackpanther
Dec 9, 2023
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1
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+473
need help
Let $x \mathbin{\spadesuit} y = \frac{x^2}{y}$ for all $x$ and $y$ such that $y\neq 0$. Find all values of $a$ such that $a \mathbin{\spadesuit} (a + 1) = 9$. Write your answer as a list separated by commas.
blackpanther
Dec 9, 2023
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+473
help plz
Let
\[f(x) = \frac{2x + 5}{x - 4} + \frac{x^2 + 1}{4x - 3}.\]
Find the inverse $f^{-1}(x)$.
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blackpanther
Dec 9, 2023
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+473
Functions
Let $f(x) = 3x - 8 + 4x^2$ and $g(x) = 15x + c - 3x^2$. Find $c$ if $(f \circ g)(x) = (g \circ f)(x)$ for all $x$.
blackpanther
Dec 9, 2023
0
2
2
+473
coeffcient
What is the coefficient of $x$ in $(x^3 + x^2 + x + 1)(x^4 - 8x^3 + 17x^2 - 23x + 14)$?
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blackpanther
Dec 8, 2023
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+473
polynomials
There exists a polynomial $f(x)$ and a constant $k$ such that
(x^2 - 2x - 5) f(x) = 2x^4 + 19x^3 + kx^2 - 15x - 1.
What is $k?$
blackpanther
Dec 8, 2023
0
1
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+473
polynomial
Find $t$ if the expansion of the product of $x^3$ and $x^2 + tx$ has no $x^2$ term.
blackpanther
Dec 8, 2023
0
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1
+473
Absolute value
Find all solutions of the equation
|x^2 - 30x - 1| + |x^2 - 30x + 29| = 30
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blackpanther
Dec 8, 2023
0
1
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+473
Inequalities
(1) Let a_1, a_2, a_3 be real numbers such that
|a_1 - a_2| + 2 |a_2 - a_3| + 3 |a_3 - a_1| = 1.
What is the largest possible value of |a_1 - a_2|?
(2) Let a_1, a_2, a_3, \dots, a_{10} be real numbers such that
read more ..
blackpanther
Dec 8, 2023
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+473
rectangle
Rectangle $ABCD$ contains a point $X$ such that $AX = 3$, $BX = 3$, and $CX = 3$. Find $DX$.
blackpanther
Dec 3, 2023
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Thanks!
blackpanther
Nov 29, 2023