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# f(x)=x^2+7 need the domain and range of the function in interval notation

f(x)=x2 +7

need the domain and range of the interval notation

### 2 Answers by Expert Tutors

Robert J. | Certified High School AP Calculus and Physics TeacherCertified High School AP Calculus and Ph...
4.6 4.6 (13 lesson ratings) (13)
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Domain: (-∞, ∞), since f(x) is defined for all real values of x.
Range: [7, ∞), since the minimum value of f(x) is 7, and f(x) is open up,  there is no upper limit.
Vivian L. | Microsoft Word/Excel/Outlook, essay composition, math; I LOVE TO TEACHMicrosoft Word/Excel/Outlook, essay comp...
3.0 3.0 (1 lesson ratings) (1)
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Hi Jim;
The domain is negative infinity to positive infinity.  The factor of x is the numerator, not the divisor.  Therefore, it can be zero.  It is also not being square-rooted.  Therefore, it can be a negative number.

The range is different because x2 will render any value of x either zero or a positive number.  We need to establish the minimum while recognizing there is no maximum.
y=02+7
y=7

The range is...
[7, positive infinity]