Diketahui fungsi f dengan rumus f (x) =-x^2

a.
[tex]f(x)=-x^2+5x-4=0\\x^2-5x+4=0\\(x-4)(x-1)=0\\(x_1,y_1)=(1,0)\\(x_2,y_2)=(4,0)[/tex]

b.
[tex]f(0)=-4[/tex]

c.
[tex]f(x)=-x^2+5x-4\\x_{\text{simetris}}=-\frac{b}{2a}=-\frac{5}{2\times (-1)}=\frac{5}{2}[/tex]

d.
[tex]y_{\text{puncak}}=f(x_{\text{simetris}})=-\left(\frac{5}{2}\right)^2+5\times\frac{5}{2}-4\\6.25+12.5-4=14.75\\\\(x,y)=(2.5,14.75)[/tex]

e.