表达式9: StartFraction, left parenthesis, "h" left parenthesis, "a" , right parenthesis minus 1 , right parenthesis Over left parenthesis, "a" minus 2 , right parenthesis , EndFractionha−1a−2
equals=
1.2 4 7 51.2475
9
This is equation of the secant line. It looks weird, but this is the usual y=mx + b form.
10
表达式11: "y" equals StartFraction, left parenthesis, "h" left parenthesis, "a" , right parenthesis minus 4 , right parenthesis Over left parenthesis, "a" minus 4 , right parenthesis , EndFraction "x" plus "h" left parenthesis, "a" , right parenthesis minus StartFraction, left parenthesis, "h" left parenthesis, "a" , right parenthesis minus 4 , right parenthesis Over left parenthesis, "a" minus 4 , right parenthesis , EndFraction left parenthesis, "a" , right parenthesisy=ha−4a−4x+ha−ha−4a−4a
