10 Minute School
Log in

Bank Jobs | বাীজগাণিতিক সূত্র ও উৎপাদক বিশ্লেষণ

বীজগাণিতিক সূত্রাবলী

(a+b)2=a²+2ab+b²(a+b)²=(ab)²+4ab(ab)²=a²2ab+b²(ab)²=(a+b)²4aba²+b²=(a+b)²2aba²+b²=(ab)²+2aba²b²=(a+b)(ab)2(a²+b²)=(a+b)²+(ab)²4ab=(a+b)²(ab)²ab=((a+b)2)²((ab)2)²(a+b+c)²=a²+b²+c²+2(ab+bc+ca)(a+b)³=a³+3a²b+3ab²+b³(a+b)³=a³+b³+3ab(a+b)(ab)³=a³3a²b+3ab²b³(ab)³=a³b³3ab(ab)a³+b³=(a+b)(a²ab+b²)a³+b³=(a+b)³3ab(a+b)a³b³=(ab)(a²+ab+b²)a³b³=(ab)³+3ab(ab)(a²+b²+c²)=(a+b+c)²–2(ab+bc+ca)2(ab+bc+ca)=(a+b+c)2(a²+b²+c²)(a+b+c)³=a³+b³+c³+3(a+b)(b+c)(c+a)a³+b³+c³–3abc=(a+b+c)(a²+b²+c²–abbcca)a³+b³+c³–3abc=(a+b+c)((ab)²+(bc)²+(ca)²) (a+b)^2= a²+2ab+b²\\ (a+b)²= (a-b)²+4ab\\ (a-b)²= a²-2ab+b²\\ (a-b)²= (a+b)²-4ab\\ a² + b²= (a+b)²-2ab\\ a² + b²= (a-b)²+2ab\\ a²-b²= (a +b)(a -b)\\ 2(a²+b²)= (a+b)²+(a-b)²\\ 4ab = (a+b)²-(a-b)²\\ ab = (\frac{(a+b)}{2})²-(\frac{(a-b)}{2})²\\ (a+b+c)² = a²+b²+c²+2(ab+bc+ca)\\ (a+b)³ = a³+3a²b+3ab²+b³\\ (a+b)³ = a³+b³+3ab(a+b)\\ (a-b)³= a³-3a²b+3ab²-b³\\ (a-b)³= a³-b³-3ab(a-b)\\ a³+b³= (a+b) (a²-ab+b²)\\ a³+b³= (a+b)³-3ab(a+b)\\ a³-b³ = (a-b) (a²+ab+b²)\\ a³-b³ = (a-b)³+3ab(a-b)\\ (a² + b² + c²) = (a + b + c) ² – 2(ab + bc + ca)\\ 2 (ab + bc + ca) = (a + b + c) 2 – (a² + b² + c²)\\ (a + b + c) ³ = a³ + b³ + c³ + 3 (a + b) (b + c) (c + a)\\ a³ + b³ + c³ – 3abc = (a+b+c)(a² + b²+ c² –ab–bc– ca)\\ a³ + b³ + c³ – 3abc = (a+b+c) ( (a–b) ²+(b–c) ² +(c–a)² )\\

উৎপাদক বিশ্লেষণ বিষয়ক সমস্যা

  • (a+b)=3,ab=2(a+b)=\sqrt{3}, a-b=\sqrt{2} হলে, 8ab(a2+b2)8ab(a^2+b^2) =?
    সমাধান:
8ab(a2+b2)=4ab.2(a2+b2)=((a+b)2(ab)2)((a+b)2+(ab)2)=((32(22)((32+(22)=(32)(3+2)=5.1=5 8ab (a^2 + b^2 )\\ = 4ab.2(a^2 + b^2 )\\ = \Big((a+b)^2 - (a-b)^2\Big) \Big((a+b)^2 + (a-b)^2\Big)\\ = \Big( (3–\sqrt{2} - (2–\sqrt{2} \Big) \Big( (3–\sqrt{2} + (2–\sqrt{2} \Big)\\ = (3-2) (3+2) = 5.1 = 5
  • (x+y)2=164,xy=32(x+y)^2=164, xy=32হলে, xyx-y=?
    Ans:

    (xy)2=(x+y)24xy=1644×32=164128=36(xy)=+6,6(x-y)^2 = (x+y)^2 - 4xy\\= 164 - 4\times 32 = 164 - 128 = 36\\ \therefore (x-y)= +6, -6
  • a+b+c=9 , ab+bc+ca= 31 হলে, a2+b2+c2a^2+b^2+c^2=?
(a+b+c)2=a2+b2+c2+2(ab+bc+ca)92=a2+b2+c2+2×318162=a2+b2+c2a2+b2+c2=19 (a+b+c)^2 = a^2 + b^2 +c^2 + 2(ab+bc+ca)\\ \Rightarrow 9^2 = a^2 + b^2 +c^2 + 2 \times 31\\ \Rightarrow 81 - 62 = a^2 + b^2 +c^2\\ \therefore a^2 + b^2 +c^2 = 19
  • If 3x – 7y = 0 and x+2y = 13 then y is_
    Ans:
    3x7y=0x=7y33x-7y=0\\ \Rightarrow x=\frac{7y}{3}

Put x=7y3x=\frac{7y}{3} into second equation, we get
7y3+2y+1313y3=13y=3\frac{7y}{3}+2y+13\\ \Rightarrow \frac{13y}{3}=13\\ \therefore y=3

Then, x=7×33=7x=\frac{7\times 3}{3}=7