I face some difficulties to find the domain

[r-soy]

I face some difficulties to find the domain

Now i put my questions and please help me to answer it

i try solve it

thanks

 

[Mark44]

It can sometimes take several hours for attachments to be approved, so for quicker responses, it's best to type your questions out so that we can see them right away.

 

[r-soy]

I think attachments are approved now >>

 

[Bohrok]

The domain of problem 46 is not all real numbers. For √x, domain is x≥0. Use that for √(-1-s).

The domain of 47 is larger than just w≥4; perhaps you were still thinking about domains with square roots. Try thinking about the domain of 1/x, or where it is undefined, and then think about the domain of (2x+3)/(w-4) again.

I can't quite make out your answer for the domain of 51, but it doesn't look right. But let's look at what you have with (y + 1)(y - 3)≥0. You know where the parabola crosses the x-axis and that it opens upward since the leading coefficient is positive. What part(s) of the graph will be above the x-axis, or ≥0?

 

[Anakin_k]

As Bohrok said, if the domain was all real numbers for √(-1-s), it would be incorrect. Say s is equal to 2. -1-2 = -3. √-3 is an imaginary number. You want to make sure whatever is under the square root bracket is equal to 0 or more.

 

[oNothinGo]

53. x^2-4x+5 and x^2+2x+3 can't be factor the way you did.

 

[Mark44]

The domain of problem 46 is not all real numbers. For √x, domain is x>0. Use that for √(-1-s).

The domain for f(x) = √x is x >= 0.

 

[Bohrok]

The domain for f(x) = √x is x >= 0.

I hit the wrong two-key combination instead of Ctrl-V. Corrected.

 

[r-soy]

46 )
1-s ≥ 0
-s ≥ - 1

47) i think domain all real numer

51 ) please i want the answer


help me .>

 

[Mark44]

46 )
1-s ≥ 0
-s ≥ - 1

No. Start with -1 -s ≥ 0
You should end up with an inequality that involves s, not -s. Review the rules for working with inequalities if needed.

47) i think domain all real numer

No. There is one real number that isn't in the domain of this function.

51 ) please i want the answer

For this function to be defined, it must be that y² -2y - 3 ≥ 0.
Factor the left hand side into two linear factors. For the product of the two factors to be ≥ 0, both factors have to be ≥ 0, or both have to be <= 0. Each case will produce its own set of numbers.

help me .>