suatu fungsi dengan rumus f(x)=ax+b jika f(4)=5 dan f(-2)= -7 , maka tentuka rumus fungsi f(x)?
Translation......we wish to write the equation of a line in the form y = mx + b given the points (4, 5) and (-2, -7)
First.....find the slope = [subtract y's in some order] / [ subtract x's in the same order]
So we have
[ -7 - 5] / [ -2 - 4] = -12/ -6 = 2
And using either point ....the point-slope form becomes
y = 2(x - 4) + 5 simplify
y = 2x - 8 + 5
y = 2x - 3
suatu fungsi dengan rumus f(x)=ax+b jika f(4)=5 dan f(-2)= -7 , maka tentuka rumus fungsi f(x)?
A function f(x) = ax + b. If f(4) = 5 and f(-2) = -7, then the function is f(x) = ?
\( f (x) = ax + b\)
\( f (4) = a\cdot 4 + b=5\)
\(a=\frac{5-b}{4}\)
\( f (-2) = -2\cdot a + b=-7\)
\(a=\frac{-7-b}{-2}\)
\(\frac{-7-b}{-2}=\frac{5-b}{4}\)
\(-28-4b=2b-10\)
\(6b=-18\\\color{blue}b=-3\)
\(a=\frac{5-b}{4}\\a=\frac{5+3}{4}\)
\(a=2\)
\(\large f(x)=2x-3\)
! Thank you C.