SOLUTION: Which function has a domain {xsuch thatx is less than 2, x is R}? a) -1/4(y-2)=(x+5)^2 b) y=3(4)(^-(x-2)) +2 c) y=log(4-2x) d) y=log base1/2 (x-2) I think the answer is (B)???

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Which function has a domain {xsuch thatx is less than 2, x is R}? a) -1/4(y-2)=(x+5)^2 b) y=3(4)(^-(x-2)) +2 c) y=log(4-2x) d) y=log base1/2 (x-2) I think the answer is (B)???      Log On


   



Question 132749: Which function has a domain {xsuch thatx is less than 2, x is R}?
a) -1/4(y-2)=(x+5)^2
b) y=3(4)(^-(x-2)) +2
c) y=log(4-2x)
d) y=log base1/2 (x-2)
I think the answer is (B)?????????

Answer by solver91311(24713) About Me  (Show Source):
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Choice a: rewrite to y=-4%28x%2B5%29%5E2%2B2. This function is defined for all real x, so x < 2 does not make this function undefined. Incorrect.

Choice b: x < 2 ensures that the exponent on 4 is positive, but there is nothing wrong with the exponent on 4 being negative or zero, so again, the domain of this function is all reals. Incorrect.

Choice c: the domain of log(x) is all positive reals. In order for 4 - 2x to be positive, x must be less than 2. This is the correct function for the given domain.

Choice d: again, the domain of log(x) is all positive reals, but in the choice d function, a value for x < 2 would make x - 2 be less than zero. The domain here is {x|x is Real, x > 2}. Incorrect.