Post a New Question

Math SAT Sheet

posted by .

1.) Find the domain and range for:

f(x)= 4x-20/ the square root of 36-x^2

2.) Solve the equation:

log6 (x-11) + log6 (x-6) = 2

3.) Solve the inequality:

x^2 - 2x - 3 is greater than 0

  • Math SAT Sheet -

    1. remember that the denominator √(36 - x^2) cannot be zero or negative,
    so shouldn't -6 < x < +6 ??

    2. log6 [(x-11)(x-6)] = 2
    (x-11)(x-6) = 6^2
    x^2 - 17x + 66 = 36
    x^2 - 17x + 30 = 0
    (x-15)(x-2) = 0
    x = 15 or x = 2

    A lot of students would stop here and think they have the right answer, but remember that we can only take logs of positive numbers, so looking at our original we can see clearly that x > 11

    so x = 15 is the only answer.

  • Math SAT Sheet -

    3. x^2 - 2x - 3 > 0
    (x-3)(x+1) > 0
    "critical" values are x = 3 and x = -1

    try a number < -1, say x = -5
    statement: (-8)(-4) > 0 ? YES
    try a number between -1 and 3, say x = 0
    statement: (-3)(1) > 0 False!
    try a number > 3, say x = 5
    statement: (2)(6)>0 YES

    so x < -1 OR x > 3, x any real number.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Pre Algebra

    Please help me with some problems. Thank you! Solve the equation by square root property. 3. 2x^2 = 26 I don't understand how to solve this problem. Solve the equation using the quadratic formula. 7. 7x^2=-8x -2 This is what I got …
  2. Algebra 2

    Can someone please explain to me how to solve logarithmic equations?
  3. MAth

    how do i find the domain and range of equations?
  4. Math

    Solve the equation. (the 6s are supposed to be sub-scripted, but I can't type subscripts) Problem: log6 7 - log6 x = 4 Choose one answer. a. 7/24 b. 7/1296 c. 7/4 d. 1296/7 I am so lost, can you please help me understand this?
  5. Math

    log6(x+7)−log6x=2 Solve for x
  6. precalulus

    Ok feeling kinda dumb because this isn't coming out right. I know it's simple. log6 (x -3) + log6(x -6) - log6(x + 1) = 2
  7. Math

    Which of the following is equal to log6(t + 1) − log6(t^2 − 1)?
  8. SAT math

    1. If square root of 3x-11 +10 = 17, find the value of 10 x . I don't know how to solve with square roots. I subtracted 10 from both sides, so I'm left with square root of 3x-11 = 7...How do I solve for x?
  9. Math

    The problem I have to solve is log with base 2 ^6 multiply by log base 6 ^ 8. I use the change of base formula and got log6/log2 * log8/log6 Which become log6/log2 * log2()^3/ log 6 I'm stuck here thanks.
  10. Math

    Solve: Log5(x-2) + log8(x-4)= log6(x-1)

More Similar Questions

Post a New Question