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Question 146648:  I NEED EXPLANATION IN A COUPLE OF MATH PROBLEMS they are all odd the answers are in the back of the book but i want to know how to do them can someone  EXPLAIN HOW TO SOLVE THEM SO I CAN BE READY FOR AN UPCOMING EXAM.i will greatly appreciated....
 
Directions: Use the function to evaluate the indicated expressions and simplify. 
27) f(x)= x + 4 ; f(x^2), (f(x))^2
 
Directions: Find the domain of the function  
37) f(x) = 2x 
41) f(x) = (1)/(x-3) 
43) f(x)= (x+2)/(x^2-1) 
45) f(x)= f(x)= squareroot of (x-5) 
 
 Answer by oscargut(2103)      (Show Source): 
You can  put this solution on YOUR website! 27) f(x)= x + 4 ; f(x^2), (f(x))^2 
 
f(x^2)= x^2+4 (you have to put x^2 instead of x) 
(f(x))^2 =(x+4)^2=x^2+8x+16
 
Directions: Find the domain of the function 
 
The domain of polynomials are all real numbers 
The domain of squareroot of f(x) are all real numbers that makes f(x)>=0 
because the squareroot of a negative number is not real 
The domain of quotient of polynomials (P(x)/Q(x)) are all real numbers that makes Q(x)not= to 0 because you can not divide by 0 
  
37) f(x) = 2x  domain are all real numbers (R) 
41) f(x) = (1)/(x-3) domain are all real numbers except {x/x-3=0} so R-{3} 
43) f(x)= (x+2)/(x^2-1) domain are all real numbers except 
 {x/x^2-1=0} so R-{1,-1} 
45) f(x)= squareroot of (x-5) 
domain are all real numbers that makes x-5>=0 so are real numbers x/x>=5  
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