Practice Test 71 - Algebra 2

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

  1. Use the inverse property blog⁡b(x)=xb^{\log_b(x)}=x (for x>0x>0) to simplify 2log⁡2(17)2^{\log_2(17)}.​
  2. In physics, the kinematic equation v2=u2+2asv^2 = u^2 + 2as relates final speed vv, initial speed uu, acceleration aa, and displacement ss. Solve v2=u2+2asv^2 = u^2 + 2as for aa (treat the other variables as constants, using the same inverse-operation reasoning as solving a numeric equation).
  3. A solution's pH is given by pH=−log⁡([H+])\text{pH}=-\log([H^+]) (base 10). If [H+]=10−7[H^+]=10^{-7}, what is the pH? Use log properties.
  4. A student graphs y=∣x−3∣+1y = |x - 3| + 1 and y=12x+4y = \frac{1}{2}x + 4 on the same coordinate plane. Based on the intersection points of these graphs, which equation below would have the same solutions?
  5. The graph shows the voltage function V(t)=12cos⁡(120πt+π3)V(t) = 12\cos(120\pi t + \frac{\pi}{3}) for an alternating current circuit. Which statement correctly interprets the phase shift and its effect on the zero crossings compared to the standard cosine function?
  6. A company analyzes three pricing strategies over time: Strategy 1 gives profit P1(t)=2t−1P_1(t) = 2^t - 1 thousand dollars, Strategy 2 gives P2(t)=t3+10tP_2(t) = t^3 + 10t thousand dollars, and Strategy 3 gives P3(t)=15t+5P_3(t) = 15t + 5 thousand dollars, where tt is time in months. At t=4t = 4, Strategy 2 yields the highest profit. What is the most likely scenario at t=15t = 15?
  7. The decibel level of a sound can be modeled by dB=10log⁡10(I/I0)\text{dB}=10\log_{10}(I/I_0), where II is the sound intensity and I0I_0 is a reference intensity. A sound has intensity 500500 times the reference (so I/I0=500I/I_0=500). Find the decibel level to the nearest tenth and interpret your result.​
  8. The sum/difference of cubes identity a3−b3=(a−b)(a2+ab+b2)a^3-b^3=(a-b)(a^2+ab+b^2) can be used with complex numbers. Let a=1+ia=1+i and b=1−ib=1-i. What is a3−b3a^3-b^3?
  9. Recognize the pattern and factor completely (sum of cubes): 8x3+278x^3+27
  10. Let f(x)=∣x∣f(x)=|x|. The graph of gg is shown along with ff. The function gg is of the form g(x)=f(x)+k.g(x)=f(x)+k. What is the value of kk? (Use the graph: ff has vertex at (0,0)(0,0) and gg has vertex at (0,3)(0,3).)
  11. Consider the expression 3x2(2x−5)+7x−43x^2(2x - 5) + 7x - 4. When this expression is written in standard form, how many terms contain xx as a factor?
  12. Use polynomial division to write x4−2x3+3x2+4x2+1\dfrac{x^4-2x^3+3x^2+4}{x^2+1} in the form q(x)+r(x)x2+1q(x)+\dfrac{r(x)}{x^2+1}, where deg⁡(r)<2\deg(r)<2.
  13. Add and express in standard form a+bia+bi: (5+3i)+(2−7i).(5+3i)+(2-7i).
  14. For the geometric series 5+15+45+135+4055+15+45+135+405, identify aa, rr, and nn, then find SnS_n (the sum of all terms shown).
  15. What is the degree of the polynomial product? (This uses the fact that polynomials are closed under multiplication and that degrees add when multiplying.) If P(x)P(x) has degree 33 and Q(x)Q(x) has degree 44, what is the degree of P(x)⋅Q(x)P(x)\cdot Q(x)?
  16. The polynomial h(x)=kx4−8x3+mx2+nx−6h(x) = kx^4 - 8x^3 + mx^2 + nx - 6 has 32\frac{3}{2} as a rational zero. If all coefficients are integers and the Rational Zero Theorem is to be applied effectively, what constraint must kk satisfy?
  17. A school is buying notebooks and folders. Let xx = number of notebooks and yy = number of folders. Constraints: - Notebooks cost $2 each and folders cost $3 each; the budget is at most $60: 2x+3y≤602x+3y\le 60. - They need at least 10 notebooks: x≥10x\ge 10. - They need at least 8 folders: y≥8y\ge 8. - Items must be whole numbers and non-negative. Which system correctly represents all constraints?
  18. A ball is thrown upward from a platform. Its height (in meters) after tt seconds is modeled by h(t)=−5(t−2)2+20h(t)=-5(t-2)^2+20 for 0≤t≤50\le t\le 5. On what interval is h(t)h(t) increasing?
  19. A cylindrical tank has volume V=πr2hV=\pi r^2 h, where rr is radius (meters) and hh is height (meters). If the height is fixed at h=3h=3 meters, what two-variable equation relates VV and rr, and what axes labels and a reasonable scale would you use to graph it for 0≤r≤50\le r\le 5?
  20. Consider the polynomial function f(x)=−2x4+8x3−6x2f(x) = -2x^4 + 8x^3 - 6x^2. After factoring completely, which statement correctly describes both the zeros and the end behavior of this function?

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