Practice Test 22 - Algebra 2

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

  1. On the same axes, f(x)=2xf(x)=2^x and g(x)=log⁡2(x)g(x)=\log_2(x) are graphed. Which statement best describes their relationship?
  2. For z=−6+8iz=-6+8i, compute zz‾z\overline{z}. (Recall zz‾=a2+b2=∣z∣2z\overline{z}=a^2+b^2=|z|^2, a real positive number.)
  3. For f(x)=(x−3)(x+2)(x−3)(x−1),f(x)=\frac{(x-3)(x+2)}{(x-3)(x-1)}, identify the zero(s), vertical asymptote(s), and any hole (removable discontinuity).​
  4. A landscaper models the length of a walkway (in feet) that can be built from xx paving stones using L(x)=2x+3L(x)=2x+3. The number of paving stones must be a whole number, and the landscaper has at most 50 stones available. Which statement best describes how the graph of LL should be represented for this context?
  5. Multiply the polynomials (use the distributive property). This demonstrates closure because the product of polynomials is a polynomial: (x2−3x+2)×(x+4).(x^2-3x+2) \times (x+4).
  6. If the remainder when p(x)=x3−2x2+kx−4p(x)=x^3-2x^2+kx-4 is divided by (x−2)(x-2) is 66, what is the value of kk? (Use remainder =p(2)=p(2).)​
  7. The complex plane below shows the real axis (horizontal) and imaginary axis (vertical). Points PP and QQ are plotted at P(3,2)P(3,2) and Q(−1,−4)Q(-1,-4). Which pair of complex numbers matches points PP and QQ? (Recall: the point (a,b)(a,b) represents a+bia+bi.)
  8. A population is modeled by P(t)=P0(1.08)tP(t)=P_0(1.08)^t, where tt is in years. Rewrite the growth part (1.08)t(1.08)^t to show an equivalent form with a quarterly growth factor raised to the number of quarters. (Use the power-of-power property.)
  9. Transform and solve by completing the square: x2+10x−3=0x^2+10x-3=0 Write it as (x−p)2=q(x-p)^2=q and then solve for xx.
  10. Use the discriminant to determine the solution type for x2−5x+6=0x^2-5x+6=0. Remember: every quadratic ax2+bx+c=0ax^2+bx+c=0 has exactly 2 complex solutions counting multiplicity (2 distinct real, 1 repeated real, or 2 complex conjugates), and the discriminant b2−4acb^2-4ac determines which case. Which statement is correct?
  11. A cyclist rides 20 miles at a speed of rr mph, then 15 miles at a speed of (r−5)(r-5) mph. The total riding time is 2.5 hours. Set up a rational equation and solve for the cyclist's speed rr on the first part. Let rr = speed (mph) for the first 20 miles, with r>5r>5.
  12. Use structure to factor x3−27x^3-27 by recognizing a difference of cubes.
  13. Let f(x)=x2−2f(x)=x^2-2 and g(x)=2x+1g(x)=2x+1. Use the intersection points of the graphs y=f(x)y=f(x) and y=g(x)y=g(x) to solve f(x)=g(x)f(x)=g(x). Which set of xx-values are the solutions?​
  14. Use synthetic division to test whether (x+2)=(x−(−2))(x+2)=(x-(-2)) is a factor of P(x)=x4−2x3−7x2+8x+12.P(x)=x^4-2x^3-7x^2+8x+12. Use c=−2c=-2 with coefficients 1,−2,−7,8,121,-2,-7,8,12. Which statement is correct? (If the remainder is 00, then it is a factor.)
  15. Divide and simplify to lowest terms. (Use "multiply by the reciprocal," like fraction division.) x2−1x2+4x+3÷x−1x+1\frac{x^2-1}{x^2+4x+3}\div\frac{x-1}{x+1} (Assume x≠−3,−1,1x \neq -3, -1, 1.)
  16. A quadratic polynomial with real coefficients can be written as ax2+bx+cax^2+bx+c with a≠0a\ne 0. In the complex numbers it always has exactly 2 zeros counting multiplicity, which previews the Fundamental Theorem of Algebra (degree-nn polynomials have exactly nn complex zeros counting multiplicity). Which statement correctly interprets "counting multiplicity" for the quadratic (x−3)2=0(x-3)^2=0?
  17. Represent the system as a matrix equation AX=BAX=B (use variable order x,y,zx, y, z): {2x+y−z=5x−3y+2z=14x+y+z=9 \begin{cases} 2x+y-z=5\\ x-3y+2z=1\\ 4x+y+z=9 \end{cases}
  18. Consider the nested expression J(x)=2(3x+1)3.J(x)=2(3x+1)^3. Chunk by viewing (3x+1)(3x+1) as a single entity. Which interpretation correctly identifies what depends on xx and what does not?
  19. Use synthetic division (instead of long division) to find the remainder when P(x)=x4−5x2+3P(x)=x^4-5x^2+3 is divided by (x+3)=(x−(−3)).(x+3)=(x-(-3)). Use c=−3c=-3 and remember to include a 00 coefficient for the missing x3x^3 and xx terms. By the Remainder Theorem, the remainder equals P(−3)P(-3). What is the remainder?
  20. A number and its reciprocal have a sum of 103\frac{10}{3}. Set up and solve an equation to find the number. Let xx = the number (and x≠0x\ne 0).

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