Practice Test 21 - Algebra 2

20 questions. Answer them in any order, then submit to see your score and every explanation.

  1. Use the Rational Zeros Theorem to list all possible rational zeros of P(x)=3x3−2x2+x−6.P(x)=3x^3-2x^2+x-6. (Remember: any rational zero pq\frac{p}{q} in lowest terms has p∣p\mid constant term and q∣q\mid leading coefficient.)​
  2. Demonstrate that the polynomial identity (x2+y2)2=(x2−y2)2+(2xy)2(x^2+y^2)^2=(x^2-y^2)^2+(2xy)^2 holds for all real x,yx,y by expanding both sides and simplifying.
  3. Four functions are defined for x≥0x\ge 0: linear f(x)=20xf(x)=20x, quadratic g(x)=5x2g(x)=5x^2, polynomial h(x)=x3h(x)=x^3, and exponential p(x)=2xp(x)=2^x. Which statement is correct about their long-term behavior?
  4. Compute the product and note it is always real and nonnegative: (6−2i)(6+2i).(6-2i)(6+2i).
  5. Condense to a single logarithm: log⁡5(x)−2log⁡5(y)+log⁡5(z)\log_5(x)-2\log_5(y)+\log_5(z) (Assume x>0x>0, y>0y>0, and z>0z>0.)
  6. A savings account balance (in dollars) after tt years is modeled by B(t)=500(1.03)tB(t)=500(1.03)^t. Mathematically, the formula works for all real tt. Realistically, the account has been open for at most 10 years and tt measures time since opening. Which choice correctly compares the mathematical and realistic domains?
  7. Function ff is given by f(x)=∣x−3∣+2f(x)=|x-3|+2. Function gg is described verbally as: "gg is an absolute value function with minimum value 1 occurring at x=−2x=-2." Which function has the smaller minimum value?
  8. A system is written in matrix form AX=BAX=B. Determine whether AA is invertible (has an inverse). If it is invertible, you may solve using X=A−1BX=A^{-1}B. A=[123246101],X=[xyz],B=[123].A=\begin{bmatrix}1&2&3\\2&4&6\\1&0&1\end{bmatrix},\quad X=\begin{bmatrix}x\\y\\z\end{bmatrix},\quad B=\begin{bmatrix}1\\2\\3\end{bmatrix}. Which statement is true?
  9. Find the modulus rr and argument θ\theta (in degrees) of the complex number 3−3i3 - 3i. Use r=a2+b2r=\sqrt{a^2+b^2} and θ=arctan⁡(ba)\theta=\arctan\left(\frac{b}{a}\right) with quadrant adjustment (argument is the angle from the positive real axis). Which polar form is correct?
  10. Consider the rational function f(x)=x2−4x−5x2−9f(x) = \frac{x^2 - 4x - 5}{x^2 - 9}. After factoring completely, which statement correctly describes the behavior of this function?
  11. Show that any exponential function g(x)=a⋅bxg(x)=a\cdot b^x (with a≠0a\neq 0, b>0b>0, b≠1b\neq 1) grows by equal factors over equal intervals. Specifically, prove that for any real number hh, the ratio g(x+h)g(x)\dfrac{g(x+h)}{g(x)} is constant with respect to xx, and connect this to why {g(n)}\{g(n)\} at integer inputs is a geometric sequence.
  12. For the logarithmic function h(x)=ln⁡(x−3)h(x) = \ln(x-3), what is the vertical asymptote?
  13. On the complex plane, let z1=3+2iz_1=3+2i and z2=1−iz_2=1-i. The distance between two complex numbers is ∣z1−z2∣=(a−c)2+(b−d)2|z_1-z_2|=\sqrt{(a-c)^2+(b-d)^2}, and the midpoint is z1+z22=(a+c2)+(b+d2)i\dfrac{z_1+z_2}{2}=\left(\dfrac{a+c}{2}\right)+\left(\dfrac{b+d}{2}\right)i. Which option gives both the distance from z1z_1 to z2z_2 and the midpoint of the segment connecting them (same formulas as in coordinate geometry for points (a,b)(a,b) and (c,d)(c,d))?
  14. Find the quotient q(x)q(x) and remainder r(x)r(x) when dividing x3+4x2−2x+7x^3 + 4x^2 - 2x + 7 by x+2x + 2, and write x3+4x2−2x+7x+2=q(x)+r(x)x+2\frac{x^3 + 4x^2 - 2x + 7}{x + 2} = q(x) + \frac{r(x)}{x + 2} with deg⁡(r)<deg⁡(x+2)\deg(r) < \deg(x + 2).
  15. On the complex plane, z=6−8iz = 6 - 8i corresponds to the point (6,−8)(6,-8). Using ∣a+bi∣=a2+b2|a+bi|=\sqrt{a^2+b^2}, what is ∣z∣|z|?
  16. Identify the zeros and their multiplicities for p(x)=x2(x−4)(x+1)2p(x)=x^2(x-4)(x+1)^2 and determine whether the graph crosses or touches at each zero.
  17. Consider the functions f(x)=5xf(x)=5x (linear), g(x)=2x2g(x)=2x^2 (quadratic), h(x)=x4h(x)=x^4 (polynomial), and p(x)=1.5xp(x)=1.5^x (exponential). Which function eventually grows fastest as x→∞x\to\infty?
  18. An investment grows according to A(t)=P (1.15)tA(t)=P\,(1.15)^t (with tt in years). Which statement correctly interprets the transformation (1.15)t=(1.151/12)12t?(1.15)^t = \left(1.15^{1/12}\right)^{12t}?
  19. A water tank is being drained at a rate that depends on the height of water remaining. The relationship between time tt (in minutes) and height hh (in feet) is inverse: as time increases, height decreases such that their product remains constant at 240. Which equation and graph characteristics correctly describe this situation?
  20. Functions ss and tt are inverses of each other. If s(3)=7s(3) = 7 and s(5)=2s(5) = 2, what is the value of t(7)−t(2)t(7) - t(2)?

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