Practice Test 58 - Algebra 2

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

  1. Let z1=7−2iz_1=7-2i and z2=1−10iz_2=1-10i be points on the complex plane. The distance between them is ∣z1−z2∣=(a−c)2+(b−d)2.|z_1-z_2|=\sqrt{(a-c)^2+(b-d)^2}. What is the distance between z1z_1 and z2z_2?
  2. The parent function f(x)=∣x∣f(x)=|x| is graphed as a V-shape with vertex at (0,0)(0,0). Consider g(x)=f(x+2)−3.g(x)=f(x+2)-3. What is the effect on the graph of ff to obtain the graph of gg?
  3. Determine the inverse function for f(x)=3x−7f(x)=3x-7.​​​
  4. Explain why f(x)=x2f(x)=x^2 needs a domain restriction to have an inverse function. Which statement best connects this to the horizontal line test?​
  5. Let z=2+5iz=2+5i and w=1−3iw=1-3i. Using the property z+w‾=z‾+w‾\overline{z+w}=\overline{z}+\overline{w}, what is z+w‾\overline{z+w}?
  6. The pH of a solution is given by pH=−log⁡10([H+])\text{pH}=-\log_{10}([H^+]), where [H+][H^+] is the hydrogen ion concentration in moles per liter. If a solution has pH 3.6, create an equation and solve for [H+][H^+]. Give your answer in scientific notation (to two significant figures) and interpret it in context.
  7. Complete the square to solve: x2+6x−2=0x^2+6x-2=0 Write the completed-square form (x−p)2=q(x-p)^2=q and then give the solutions.
  8. A bacteria culture starts with 500 bacteria and doubles every 3 hours. After how many hours will the population first exceed 10,000 bacteria?
  9. Consider the functions f(x)=5xf(x)=5x (linear), g(x)=x3g(x)=x^3 (cubic polynomial), h(x)=x5h(x)=x^5 (5th-degree polynomial), and p(x)=2xp(x)=2^x (exponential). Order these functions by eventual growth rate (for sufficiently large xx).​
  10. An investment grows according to A(t)=5000(1.06)tA(t) = 5000(1.06)^t dollars after tt years. How long will it take for the investment to triple in value?
  11. The function ff is one-to-one, so it has an inverse. A point on the graph of ff is (7,−3)(7,-3). Using the fact that (a,b)(a,b) on ff corresponds to (b,a)(b,a) on f−1f^{-1}, what is f−1(−3)f^{-1}(-3)?
  12. Use polynomial division to express 2x3−x2+0x+3x2+1\frac{2x^3-x^2+0x+3}{x^2+1} in the form q(x)+r(x)x2+1q(x)+\frac{r(x)}{x^2+1}, where deg⁡(r)<2\deg(r)<2.
  13. Possible rational zeros of P(x)=x3−4x2+x+6P(x)=x^3-4x^2+x+6 (from the Rational Zeros Theorem) are ±1,±2,±3,±6\pm 1,\pm 2,\pm 3,\pm 6. Which of these candidates are actual zeros? (Test by substitution or synthetic division.)
  14. Simplify using logarithm properties: log⁡7(49x)−log⁡7(7)\log_7(49x)-\log_7(7) (Assume x>0x>0.)
  15. Which statement correctly applies the Rational Zeros Theorem to P(x)=6x3−x2+4x−5?P(x)=6x^3-x^2+4x-5?​
  16. Multiply and simplify using i2=−1i^2 = -1: (3+2i)(1−4i)(3 + 2i)(1 - 4i). Write your answer in a+bia + bi form.
  17. Use polynomial long division to write x4−3x2+5x2+1\frac{x^4 - 3x^2 + 5}{x^2 + 1} in the form q(x)+r(x)x2+1q(x) + \frac{r(x)}{x^2+1}, where deg⁡(r)<2\deg(r) < 2.
  18. A phone battery starts at 100% and loses 9% of its remaining charge each hour while streaming video. Create an exponential model for the battery percentage after tt hours, then determine how long until the battery reaches 20%. Round to the nearest tenth of an hour and interpret your answer.
  19. A bike rental shop charges a one-time service fee of $12 plus $5 per hour. 1) Write an equation for the total cost CC (dollars) in terms of hours rented hh (hours). 2) Then choose the best axes labels and reasonable scales to graph the relationship for 0≤h≤100\le h\le 10. Which choice gives both the correct equation and an appropriate graph setup?​
  20. A bacteria culture starts with 200 cells and grows by 10% each hour. Let tt be the number of hours. What function models the population P(t)P(t)?

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