Practice Test 9 - Algebra 2

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

  1. Determine whether the system has one solution, no solution, or infinitely many solutions: {2x+y=54x+2y=12\begin{cases} 2x + y = 5\\ 4x + 2y = 12 \end{cases}
  2. A gym charges members according to the cost function C=25m+40C = 25m + 40, where CC is the total cost in dollars and mm is the number of months of membership. In the function, what does the parameter 4040 represent in context?
  3. For which values of xx is the expression x2−9x2+x−12÷x+3x−3\frac{x^2 - 9}{x^2 + x - 12} \div \frac{x + 3}{x - 3} undefined?
  4. Find the polar form of −5i-5i as r(cos⁡θ+isin⁡θ)r(\cos\theta + i\sin\theta) with θ\theta in degrees, where r=a2+b2r=\sqrt{a^2+b^2} and θ\theta is the argument measured from the positive real axis.
  5. A geometric series has first term a=12a=12, common ratio r=−13r=-\tfrac{1}{3}, and n=5n=5 terms. Find S5S_5.
  6. A medicine amount in the bloodstream is recorded every hour: Hour: 0, 1, 2, 3 Amount (mg): 80, 68, 57.8, 49.13 Classify: exponential growth, exponential decay, or neither. If exponential, what percent does it change per hour?
  7. Solve 6⋅10t/3=156\cdot 10^{t/3}=15 for tt. Express the solution as a logarithm and then approximate using technology.
  8. For f(x)=2x2−5x2+4,f(x)=\frac{2x^2-5}{x^2+4}, what is the horizontal asymptote?​
  9. A gym membership costs $25 per month plus a one-time sign-up fee of $60. Let mm be the number of months. Write an equation for total cost CC (dollars) in terms of mm and choose appropriate axes labels and scale to graph for 0≤m≤120\le m\le 12. Which choice is correct?​
  10. Which set of points on the complex plane represents all complex numbers zz such that ∣z∣=4|z|=4? (Here ∣z∣|z| is the distance from the origin.)
  11. Convert the system to matrix form AX=BAX=B (use variable order x,yx, y): {4x−y=2−3x+6y=15 \begin{cases} 4x-y=2\\ -3x+6y=15 \end{cases}
  12. Two points on the complex plane are z1=−4+1iz_1=-4+1i and z2=2−5iz_2=2-5i. Using the coordinate-geometry distance formula written for complex numbers, ∣z1−z2∣=(a−c)2+(b−d)2|z_1-z_2|=\sqrt{(a-c)^2+(b-d)^2}, what is the distance between them?
  13. A quadratic expression in the form x2+bx+cx^2 + bx + c has been factored as (x+4)(x−7)(x + 4)(x - 7). What is the sum of the coefficients b+cb + c?
  14. Solve f(x)=16f(x)=16 where f(x)=2x3f(x)=2x^3, and express the result as f−1(16)f^{-1}(16).​​​
  15. If log⁡2(x)=7\log_2(x)=7, find xx by rewriting in exponential form.
  16. Possible rational zeros of P(x)=x3−4x2+x+6P(x)=x^3-4x^2+x+6 are ±1,±2,±3,±6\pm 1,\pm 2,\pm 3,\pm 6. Which of these candidates are actual zeros? (You may test by substitution.)
  17. Use p(a)p(a) to find the remainder for division by (x−a).(x-a). If p(x)=x4−x2+2x−6,p(x)=x^4-x^2+2x-6, what is the remainder when dividing by (x−2)?(x-2)?
  18. Graph the rational function f(x)=(x−2)(x+1)(x−4)(x+3)f(x)=\frac{(x-2)(x+1)}{(x-4)(x+3)} identifying zeros, vertical asymptotes, and the horizontal asymptote (end behavior).
  19. What is the horizontal asymptote of the exponential function p(x)=2x+4p(x)=2^x+4? (Connect to the parent function y=2xy=2^x.)
  20. A physics student needs to determine the acceleration of an object given the formula F=ma+kv2F = ma + kv^2, where FF is the total force, mm is mass, aa is acceleration, kk is a drag coefficient, and vv is velocity. Which expression correctly isolates the acceleration?

Practice tests