Practice Test 57 - Algebra 2

19 of the 20 questions below are in this test; the other one can't be scored yet. Answer them in any order, then submit to see your score and every explanation.

  1. Solve the quadratic equation by taking square roots: (x−4)2=9.(x-4)^2=9.
  2. A function h(x)=−x2+8x−7h(x) = -x^2 + 8x - 7 is defined on the interval [0,8][0, 8]. To create an invertible function, Maria restricts the domain to [0,4][0, 4] and Jose restricts it to [4,8][4, 8]. Which statement about their restricted functions is correct?
  3. How does the graph behave at each zero of p(x)=(x+1)(x−2)4?p(x)=(x+1)(x-2)^4? Also state the end behavior.
  4. Order the following functions by eventual growth rate (from fastest to slowest) as x→∞x\to\infty: - Linear: f(x)=20xf(x)=20x - Quadratic: g(x)=x2g(x)=x^2 - Polynomial (degree 5): h(x)=x5h(x)=x^5 - Exponential: p(x)=1.3xp(x)=1.3^x​
  5. Simplify the expression (23)t\left(2^3\right)^t using the power-of-a-power property.​​
  6. Verify whether the point (2,3)(2,3) is a solution to the linear-quadratic system (a solution must satisfy both equations). {y=x2−1y=3x−3\begin{cases} y = x^2 - 1 \\ y = 3x - 3 \end{cases} Which statement is correct?
  7. Rewrite the logarithmic equation log⁡5(125)=3\log_5(125)=3 in exponential form using by=x⇔log⁡b(x)=yb^y=x \Leftrightarrow \log_b(x)=y.​
  8. Over C\mathbb{C}, you can factor expressions using standard identities even when no real factorization exists. Factor x4+4x^4+4 completely over C\mathbb{C}.
  9. Write the system of equations as a single matrix equation AX=BAX=B (use variable order x,yx, y): {3x+2y=8x−5y=−3 \begin{cases} 3x+2y=8\\ x-5y=-3 \end{cases}
  10. Multiply and simplify using i2=−1i^2=-1: (3+2i)(1−4i).(3+2i)(1-4i).
  11. Which statement best matches the "Fundamental Theorem for quadratics" idea: a degree-2 polynomial ax2+bx+cax^2+bx+c has exactly 2 complex zeros counting multiplicity, with the discriminant b2−4acb^2-4ac determining whether they are 2 distinct real, 1 repeated real, or 2 complex conjugates? (This also previews the Fundamental Theorem of Algebra: degree nn has nn complex zeros counting multiplicity.)
  12. Which choice correctly identifies AA, XX, and BB for the system (use variable order x,yx, y)? {4x−y=10−3x+6y=−12 \begin{cases} 4x-y=10\\ -3x+6y=-12 \end{cases}
  13. Factor completely over the complex numbers: x4+4x^4+4. (Hint: use a2+b2=(a+bi)(a−bi)a^2+b^2=(a+bi)(a-bi) with a=x2a=x^2 and b=2b=2.)
  14. A radioactive sample's mass is recorded every day: Day: 0, 1, 2, 3 Mass (g): 50, 46, 42, 38 Does this represent constant percent decay? (Hint: constant percent change means a constant ratio, not a constant difference.)
  15. A fireworks shell's height above the ground (in meters) tt seconds after launch is modeled by h(t)=−5(t−2)2+20h(t)=-5(t-2)^2+20, for 0≤t≤50\le t\le 5. Identify the maximum height of the shell and when it occurs.
  16. Use the table to approximate the solution to f(x)=g(x)f(x)=g(x), where f(x)=x3f(x)=x^3 and g(x)=2x+5g(x)=2x+5. Choose the best estimate for the solution to the nearest tenth.
  17. The function f(x)=7x−3f(x)=7x-3 represents a relationship between xx and f(x)f(x). Is the rate of change constant? If yes, what is it?
  18. A polynomial function p(x)p(x) has the property that p(x)=x2(x2−9)(2x−6)p(x) = x^2(x^2 - 9)(2x - 6). When analyzing this function's complete behavior, which statement identifies the most significant graphical feature that distinguishes it from simpler polynomial functions?
  19. Factor and graph p(x)=x3−4xp(x)=x^3-4x showing all zeros and the correct end behavior.
  20. A toy rocket's height (in feet) after tt seconds is modeled by h(t)=−16t2+64th(t)=-16t^2+64t. In the real situation, the rocket is launched from the ground at t=0t=0 and returns to the ground when h(t)=0h(t)=0 again. What is an appropriate realistic domain for tt?

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