Wiedząc, że
W(x)=2x^3-3x^2+20
Oblicz
a)
W(-1)=2*(-1)^3-3*(-1)^2+20=-2-3+20=15
b)
W(\sqrt3)=2*\sqrt{3^3}-3*\sqrt{3^2}+20=2*3\sqrt3-3*3+20=6\sqrt3+11
c)
W(1-\sqrt2)=2*(1-\sqrt2)^3-3(1-\sqrt2)^2+20=
=2(1-3\sqrt2+3*2-\sqrt{2^3})-3(1-2\sqrt2+2)+20=
=2(7-3\sqrt2-2\sqrt2)-3+6\sqrt2-6+20=
=2(7-5\sqrt2)+11+6\sqrt2=
=14-10\sqrt2+11+6\sqrt2=
=25+4\sqrt2