Tính
A= 1/( căn 25+ căn +24) + 1/( căn 23+ căn 22)+...+ 1/(căn 2 +1)
Tính:
\(M=\dfrac{1}{2\sqrt{1}+1\sqrt{2}}+\dfrac{1}{3\sqrt{2}+2\sqrt{3}}+...+\dfrac{1}{25\sqrt{24}+24\sqrt{25}}\)
Tính \(S=\frac{1}{2\sqrt{1}+1\sqrt{2}}+\frac{1}{3\sqrt{2}+2\sqrt{3}}+...+\)\(\frac{1}{25\sqrt{24}+24\sqrt{25}}\)
Vẽ đồ thị hàm số:
1, y = 1/4x mũ 2
2, y = -1/4 x mũ 2
3, y = -2 x mũ 2
4, y = -1/2 x mũ 2
5, y = 3 x mũ 2
Tính nhanh:
A=1+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20=
B=20+21+22+23+24+25=
C=26+27+28+29+30+31+32+33=
D=1+(tổng các số đến 100)=
Tính
P=\(\frac{1}{2\sqrt{1}+1\sqrt{2}}\)+\(\frac{1}{3\sqrt{2}+2\sqrt{3}}\)+.................+\(\frac{1}{25\sqrt{24}+24\sqrt{25}}\)
CMR:
\(\frac{1}{2\sqrt{1}+1\sqrt{2}}+\frac{1}{3\sqrt{2}+2\sqrt{3}}+\frac{1}{4\sqrt{3}+3\sqrt{4}}+...+\frac{1}{25\sqrt{24}+24\sqrt{25}}< 1\)
\(A=\frac{\sqrt{2}-\sqrt{1}}{2+1}+\frac{\sqrt{3}-\sqrt{2}}{3+2}+...+\frac{\sqrt{25}+\sqrt{24}}{25+24}\)
CMR A<0,4
Tính A=\(\frac{1}{\sqrt{1}+\sqrt{2}}+\frac{1}{\sqrt{2}+\sqrt{3}}+\frac{1}{\sqrt{3}+\sqrt{4}}+...+\frac{1}{\sqrt{24}+\sqrt{25}}\)