Practice Test 35 - Algebra 2

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

  1. For the polynomial T(x)=2x4−3x3+x2−4x+5T(x) = 2x^4 - 3x^3 + x^2 - 4x + 5, suppose that when T(x)T(x) is divided by (x−a)(x - a), the remainder is rr. What is the remainder when T(2x)T(2x) is divided by (x−a2)(x - \frac{a}{2})?
  2. Which restriction(s) make f(x)=x2−4xf(x)=x^2-4x pass the horizontal line test and therefore have an inverse? (Choose the best answer.)
  3. The sequence is defined recursively by a1=6a_1=6 and an+1=12ana_{n+1}=\tfrac{1}{2}a_n. Write the explicit formula for ana_n (treating it as a function with integer domain n≥1n\ge 1).
  4. Factor and sketch f(x)=x4−5x2+4f(x)=x^4-5x^2+4 showing all real zeros and the end behavior.
  5. Given t(x)=2x+1x−3t(x) = \frac{2x + 1}{x - 3} where x≠3x \neq 3, if t−1(x)t^{-1}(x) exists, what is the domain of t−1(x)t^{-1}(x)?
  6. A school club is making gift bags using stickers and pencils. Let xx be the number of sticker packs and yy be the number of pencil packs purchased. Each sticker pack costs $4 and each pencil pack costs $6. The club has at most $72 to spend, needs at least 10 total packs, and cannot buy negative amounts. Which system of inequalities represents all constraints?
  7. Use the identity a2−b2=(a+b)(a−b)a^2-b^2=(a+b)(a-b), which remains valid for complex a,ba,b, to evaluate (1+i)2−(2−i)2.(1+i)^2-(2-i)^2.
  8. Rationalize the denominator using the conjugate and write in a+bia+bi form: 2−i3+2i.\frac{2-i}{3+2i}.
  9. What is the 4th term (counting from the first term as term 1) in the expansion of (x+y)6?(x+y)^6?
  10. Compute the product using the conjugate pair identity (a+bi)(a−bi)=a2+b2(a+bi)(a-bi)=a^2+b^2: (4+3i)(4−3i).(4+3i)(4-3i).. Give your answer in simplest form.
  11. A quadratic with no real zeros can still factor over C\mathbb{C}. Which option correctly factors P(x)=x2+2x+5P(x)=x^2+2x+5 over the complex numbers?
  12. A geometric series is the sum of terms of a geometric sequence. For the finite geometric series Sn=a+ar+ar2+⋯+arn−1,S_n=a+ar+ar^2+\cdots+ar^{n-1}, derive a formula for SnS_n (assume r≠1r\ne 1) by multiplying by rr and subtracting so that the middle terms cancel.
  13. A ball is thrown upward from a height of 6 feet. The function h(t)=−16t2+32t+6h(t) = -16t^2 + 32t + 6 models the height of the ball in feet after tt seconds. Which statement correctly interprets a key feature of this function in the context of the problem?
  14. Let the parent function be f(x)=xf(x)=\sqrt{x}. Describe the effect of replacing f(x)f(x) with g(x)=f(2x)g(x)=f(2x).
  15. Use synthetic division (a streamlined alternative to long division for (x−c)(x-c)) to divide P(x)=x3−6x2+11x−6P(x)=x^3-6x^2+11x-6 by (x−3)(x-3). Use c=3c=3 and coefficients 1,−6,11,−61,-6,11,-6. The bottom row gives the quotient coefficients and the remainder, and the remainder equals P(3)P(3) by the Remainder Theorem. What is the quotient and remainder?
  16. What is the coefficient of x3y3x^3y^3 in the expansion of (x+y)6?(x+y)^6? (You may use Pascal's Triangle.)
  17. Use technology (for a 3×33\times 3 matrix) to solve the system by writing it as AX=BAX=B and using X=A−1BX=A^{-1}B. \begin{align*} x+y+z&=6\\ 2x-y+z&=3\\ x+2y-z&=2 \end{align*} What is (x,y,z)(x,y,z)?
  18. Consider F(x)=x2(x+1)−4(x+1).F(x)=x^2(x+1)-4(x+1). If you view (x+1)(x+1) as a single factor, which statement best describes the structure revealed by chunking?
  19. Derive the finite geometric series sum formula for r≠1r\ne 1. Start with Sn=a+ar+ar2+⋯+arn−1.S_n=a+ar+ar^2+\cdots+ar^{n-1}. Multiply both sides by rr and subtract to eliminate the middle terms. Which expression correctly gives SnS_n?
  20. Use the identity (x2+y2)2=(x2−y2)2+(2xy)2(x^2+y^2)^2=(x^2-y^2)^2+(2xy)^2 to generate a Pythagorean triple when x=3x=3 and y=2y=2. (A Pythagorean triple is (a,b,c)(a,b,c) with a2+b2=c2a^2+b^2=c^2.)

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