document.write( "Question 453993: Find the values of a and b that make f continuous everywhere.
\n" ); document.write( "f (x)=
\n" ); document.write( "{
\n" ); document.write( "x2−4x−2 if x<2
\n" ); document.write( "ax2−bx+3 if 2≤x<3
\n" ); document.write( "2x−a+b if x≥3 }\r
\n" ); document.write( "\n" ); document.write( "I dont understand how i would solve this. Please help. Thank you. :)
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Algebra.Com's Answer #311808 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Find the values of a and b that make f continuous everywhere.
\n" ); document.write( "f (x)=
\n" ); document.write( "{
\n" ); document.write( "1. x^2−4x−2 if x<2
\n" ); document.write( "2. ax2−bx+3 if 2≤x<3
\n" ); document.write( "3. 2x−a+b if x≥3 }
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\n" ); document.write( "Evaluate \"1\" at x = 2
\n" ); document.write( "f(2) = 2^2-4*2-2 = -6
\n" ); document.write( "--------------
\n" ); document.write( "Evaluate \"3\" at x = 3
\n" ); document.write( "g(3) = 2(3)-a+b = 6-a+b
\n" ); document.write( "----
\n" ); document.write( "So two of the points of \"2\" must be (2,-6) and (3,6-a+b)
\n" ); document.write( "____
\n" ); document.write( "Substitute those coordinates into \"2\"
\n" ); document.write( "to solve for \"a\" and for \"b\".
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\n" ); document.write( "2. ax2−bx+3
\n" ); document.write( "----
\n" ); document.write( "(2,-6) gives you 4a-2b+3 = -6
\n" ); document.write( "2a - b = -9
\n" ); document.write( "---
\n" ); document.write( "(3,6-a+b) gives you a(9)-b(3)+3 = 6-a+b
\n" ); document.write( "10a - 4b = 3
\n" ); document.write( "--------------------
\n" ); document.write( "Solve the system:
\n" ); document.write( "2a - b = -9
\n" ); document.write( "10a -4b = 3
\n" ); document.write( "----------------------
\n" ); document.write( "Multiply thru 1st equation by 5:
\n" ); document.write( "10a - 5b = -45
\n" ); document.write( "10a - 4b = 3
\n" ); document.write( "---
\n" ); document.write( "Subtract to get:
\n" ); document.write( "b = 48
\n" ); document.write( "---
\n" ); document.write( "Solve for \"a\":
\n" ); document.write( "2a - b = -9
\n" ); document.write( "2a - 48 = -9
\n" ); document.write( "2a = 39
\n" ); document.write( "a = 39/2
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\n" ); document.write( "I'd suggest you check alll the arithmetic
\n" ); document.write( "here as mistakes can creep in.
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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