Practice Test 44 - Algebra 2

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

  1. Convert the complex number −2+2i-2+2i from rectangular form a+bia+bi to polar form r(cos⁡θ+isin⁡θ)r(\cos\theta+i\sin\theta). Use r=a2+b2r=\sqrt{a^2+b^2} and θ=arctan⁡ ⁣(ba)\theta=\arctan\!\left(\frac{b}{a}\right) with the correct quadrant adjustment. (Angle in degrees; θ\theta is the argument measured counterclockwise from the positive real axis.)
  2. The function f(x)=x−2f(x)=\sqrt{x-2} can be used to model the side length (in meters) of a square when xx represents the measured area (in square meters) plus 2. What is the realistic domain for xx?
  3. Condense to a single logarithm: 3ln⁡(u)+ln⁡(v)−2ln⁡(w)3\ln(u)+\ln(v)-2\ln(w) (Assume u>0u>0, v>0v>0, and w>0w>0.)
  4. Simplify using the inverse relationship between exponentials and logarithms: log⁡3(38)\log_3(3^8).
  5. An investment account starts with $1200 and earns 6%6\% interest compounded annually. Model the situation with an exponential equation and solve for how many years tt it will take the balance to reach $2000. Let tt = time in years.​
  6. Using the fact that (a+bi)(a−bi)=a2+b2(a+bi)(a-bi)=a^2+b^2, compute (2+5i)(2−5i)(2+5i)(2-5i).
  7. The geometric sequence 3, 6, 12, 24,…3,\ 6,\ 12,\ 24,\dots defines values of a function at integer inputs with g(1)=3g(1)=3, g(2)=6g(2)=6, g(3)=12g(3)=12, etc. Write an exponential function g(x)g(x) that extends this pattern.
  8. A rectangle has an area of 96 cm2^2. Its length is 4 cm more than its width. Write and solve a quadratic equation to find the rectangle's width. Let ww = the width in cm.
  9. Does the table show a constant rate of change? Use Δy/Δx\Delta y/\Delta x for each interval. Table (equal xx-intervals of 1): xx: 1, 2, 3, 4 yy: 2, 6, 12, 20
  10. A community garden is planning crops. Let cc = acres of corn and ss = acres of soybeans. Constraints: - Total land available: at most 60 acres: c+s≤60c+s\le 60. - Water available: at most 100 acre-ft. Corn uses 2 acre-ft per acre; soybeans use 1.5 acre-ft per acre. - At least 10 acres of corn must be planted. - Nonnegativity: c≥0c\ge 0, s≥0s\ge 0. Which system correctly represents all constraints?
  11. Identify zeros and their multiplicities for p(x)=x(x−2)3(x+1).p(x)=x(x-2)^3(x+1). Also state whether the graph crosses or touches the x-axis at each zero and give the end behavior.
  12. Let f(x)=x2f(x)=x^2. Compare the transformations g1(x)=2f(x)g_1(x)=2f(x) and g2(x)=f(2x)g_2(x)=f(2x). Which statement is correct?
  13. On the complex plane, the difference z1−z2z_1-z_2 represents the vector from z2z_2 to z1z_1, and its modulus gives the distance: ∣z1−z2∣=(a−c)2+(b−d)2|z_1-z_2|=\sqrt{(a-c)^2+(b-d)^2}. What is the distance between z1=2+3iz_1=2+3i and z2=−1+7iz_2=-1+7i?
  14. Given the explicit formula an=9+4(n−1)a_n=9+4(n-1), write an equivalent recursive definition (domain: positive integers).
  15. Consider two investment accounts. Account A starts with $500 and increases by $75 each month. Account B starts with $200 and doubles every 3 months. After how many months will Account B first exceed the value predicted by the linear growth pattern if Account A were to maintain a constant monthly increase?
  16. A car rental company charges a fixed fee plus a per-day fee. The total cost is modeled by C=45d+60C = 45d + 60, where CC is in dollars and dd is the number of days rented. In the equation C=45d+60C = 45d + 60, what does the 60 mean in context?
  17. Use technology to solve AX=BAX=B using the inverse method X=A−1BX=A^{-1}B. A=[110011101],X=[xyz],B=[354]A=\begin{bmatrix}1&1&0\\0&1&1\\1&0&1\end{bmatrix},\quad X=\begin{bmatrix}x\\y\\z\end{bmatrix},\quad B=\begin{bmatrix}3\\5\\4\end{bmatrix} What is XX?
  18. A signal is represented by the complex number z=3+iz=\sqrt{3}+i in rectangular form a+bia+bi. Convert it to polar form r(cos⁡θ+isin⁡θ)r(\cos\theta+i\sin\theta), where r=a2+b2r=\sqrt{a^2+b^2} and θ\theta is the argument measured counterclockwise from the positive real axis. (Angle in degrees.)
  19. Which rational function has a horizontal asymptote at y=−2y = -2 and vertical asymptotes at x=1x = 1 and x=−4x = -4?
  20. In geometry, the volume of a sphere is V=43πr3V=\dfrac{4}{3}\pi r^3. Solve for the radius rr in terms of VV.

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