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Logarithmic and Square Root Graphs - Quiz 2   Last unanswered question  Question  Next unanswered question

Question 1 lion

Consider the graph below.

PIC
Which function is best described by this graph?
a) y = ex.   b) √-- y = x .
c) y = ln(x + 1)   d) y = lnx .

 

Not correct. Choice (a) is false.
Try again,   y = ex   is always positive.
Not correct. Choice (b) is false.
Try again,   √-- y = x   is always positive
Your answer is correct.
This graph has a logarithmic shape and at  x = 0   we have  y = ln(0+ 1) = 0 .
Not correct. Choice (d) is false.
Try again, this graph has the right shape but  lnx   is undefined at  x = 0,
This graph is defined at  x = 0,
Question 2 lion

Which of the following graphs represents  y = √x-?
a) PIC   b) PIC
c) PIC   d) PIC

 

Not correct. Choice (a) is false.
Try again, this is  y = lnx .
Not correct. Choice (b) is false.
Try again, this is  y = ex.
Not correct. Choice (c) is false.
Try again, this is  √ ----- y = x +1 .
Remember  √ - 0 = 0 .
Your answer is correct.
This is  √ -- y = x.
Question 3 lion

What is the value of  f(x) = 3 - 2 ln x   at   x = 1?
a) f(1) = 1.   b) f(1) = 3 .
c) f(1) = 5 .   d) f(1)   is undefined.

 

Not correct. Choice (a) is false.
Try again, remember  ln1 = 0.
Your answer is correct.
Since  ln1 = 0   we have  3- 2ln1 = 3- 0.
Not correct. Choice (c) is false.
Try again, remember  ln1 = 0.
Not correct. Choice (d) is false.
Try again, remember  ln1 = 0.
Question 4 lion

What is the value of  √ -- f(x) = x- 5   at  x = 1?
a) f (1) = 4.   b) f(1) = - 2.
c) f(1) = - 4,.   d) The function is undefined at x = 1 .

 

Not correct. Choice (a) is false.
Try again, watch for negative numbers.
Not correct. Choice (b) is false.
Try again, you must evaluate  √- 1   first.
Your answer is correct.
√- f(1) = 1 - 5 = 1 - 5 = - 4 .
Not correct. Choice (d) is false.
Try again, you must evaluate  √- 1   first.
Question 5 lion

Consider the graph below.

PIC
Which function is best described by this graph?
a) 1 2 f (x) = 4x - 4x + 12.   b) √ -- f(x) = 4 - x.
c) - (x-1) f(x) = 4e - 3.   d) f(x) = 4 - 3lnx.

 

Not correct. Choice (a) is false.
Try again, this is not a parabola.
Not correct. Choice (b) is false.
Try again,   f (0) = 4   in this function.
Not correct. Choice (c) is false.
Try again,   0 f(1) = 4e - 3 = 1   not 4.
Your answer is correct.
This is the right shape for y = a - bln x and it passes through   (1,4)
so it is   y = 4- blnx   and this is the only choice of this type.