Examples
Last updated at December 16, 2024 by Teachoo
Transcript
Question 3 (Supplementary NCERT) ā«1āš„ ā(1+š„āš„^2 ) šš„ ā«1āš„ ā(1+š„āš„^2 ) šš„ We can write it as:- x = A [š/šš„ (1+š„āš„^2 )]+ B x = A [0+1ā2š„]+ B x = A [1ā2š„]+ B x = "A"ā2"A" š„+ B x = ā2"A" š„+(š“+šµ) Comparing x and constant term Thus, we can write x = A [1ā2š„] + B x = ((ā1)/2)[1ā2š„] + 1 x = (ā2A) x š„/š„ = ā2A 1 = ā2A A = (ā1)/2 0 = A + B B = āA B = ā((ā1)/2) B = 1/2 Integrating ā«1āćš„ā(1+š„āš„^2 ) ć šš„ = ā«1āć[(ā1/2)[1ā2š„]+1/2] ć ā(1+š„āš„^2 ) šš„ = ā«1āć[(ā1/2)[1 ā2š„] ā(1+š„āš„^2 )+1/2 ā(1+š„āš„^2 )] ć šš„ = ā«1āć(ā1/2)[1ā2š„] ā(1+š„āš„^2 ) šš„+ć ā«1āć1/2 ā(1āš„āš„^2 )ć šš„ = ā1/2 ā«1āć[1ā2š„] ā(1+š„āš„^2 ) šš„+ć 1/2 ā«1āā(1+š„āš„^2 ) šš„ Solving š°_š I_1 = (ā1)/2 ā«1āć[1ā2š„] ā(1+š„āš„^2 )ć šš„ Let 1 + š„ ā š„^2 = t Diff. both sides w.r.t.x 0 + 1 ā2x = šš”/šš„ (1 ā 2x) dx = dt dx = šš”/(1 ā 2š„) Thus, our equation becomes I_1 = (ā1)/2 ā«1āć[1ā2š„] ā(1+š„āš„^2 )ć šš„ Putting the value if (1+š„āš„^2) and dx, we get I_1 = (ā1)/2 ā«1āć[1ā2š„] āš”ć. šš„ I_1 = (ā1)/2 ā«1āć[1ā2š„] āš”ć. šš”/[1 ā 2š„] š¼_1 = (ā1)/2 ā«1āāš”. šš” I_1 = (ā1)/2 ā«1āć(š”)ć^(1/2) šš” I_1 = (ā1)/2 ćš” ć^(1/2 + 1)/((1/2 + 1) )+ C_1 I_1 = (ā1)/2 ćš” ć^(3/2 )/((3/2) )+ C_1 I_1 = (ā1)/3 ćš” ć^(3/2 )+ C_1 I_1 = (ā1)/3 ć(1āš„ āš„^2 ) ć^(3/2 )+ C_1 ("Using t = " 1āš„ āš„^2 ) Solving š°_š I_2 = 1/2 ā«1āā(1+š„āš„^2 ) šš„ I_2 = 1/2 ā«1āā(ā(š„^2āš„ā1)) šš„ I_2 = 1/2 ā«1āā(ā[š„^2ā2(š„)(1/2)ā1] ) šš„ I_2 = 1/2 ā«1āćā(ā[š„^2ā2(š„)(1/2)+(1/2)^2ā(1/2)^2ā1] ) ć šš„ I_2 = 1/2 ā«1āćā(ā[(š„ā1/2)^2ā(1/2)^2ā1] ) ć šš„ I_2 = 1/2 ā«1āćā(ā[ć (š„ā1/2)ć^2+(ā1 ā4)/4] ) ć šš„ I_2 = 1/2 ā«1āćā(ā[ć (š„ā1/2)ć^2 ā5/4] ) ć šš„ I_2 = 1/2 ā«1āćā(5/4 ć ā(š„ā1/2)ć^2 ) ć šš„ I_2 = 1/2 ā«1āćā((ā5/4)^2 ć ā(š„ā1/2)ć^2 ) ć šš„ I_2 = 1/2 ((š„ ā 1/2)/2 ā((ā5/4)^2 ć ā(š„ā1/2)ć^2 )+(ā5/2)^2/2 ćš ššć^(ā1) ((š„ + 1/2)/(ā5/2))+ C_2 ) I_2 = 1/2 (((2š„ ā1)/2)/2 ā(5/4ā[š„^2 +1/4ā2š„(1/2)] ) +(5/4)/2 ćš ššć^(ā1) (((2š„ ā 1)/2)/(ā5/2))+ C_2 ) It is of form ā(š^2āš„^2 ) šš„=1/2 š„ā(š^2āš„^2 )+š^2/2 ćš ššć^(ā1) š„/š+ C_2 Replacing x by (x ā 1/2) and a by ā5/2 , we get I_2 = 1/2 ((2š„ ā1)/4 ā(5/4ā[š„^2 +1/4 āš„] ) +5/8 ćš ššć^(ā1) ((2š„ ā 1)/ā5)+ C_2 ) I_2 " = " (2š„ ā1)/8 ā(1+š„+š„^2 ) +5/16 ćš ššć^(ā1) ((2š„ ā 1)/ā5)+C_3 Putting the value of I_1 and I_2 in (1) ā«1āš„ ā(1+ š„āš„^2 ) dš„ = (ā1)/2 ā«1āć[1ā2š„] ā(1+š„āš„^2 )ć šš„+ā«1āā(1+š„āš„^2 ) šš„ = (ā1)/3 ć(1+š„āš„^2)ć^(3/2) + C_1 + ((2š„ ā1))/8 ā(1+š„āš„^2 )+5/16 ćš ššć^(ā1) ((2š„ ā 1)/ā5)+ C_3 = (āš)/š ć(š+šāš^š)ć^(š/š) +š/š (šš āš) ā(š+šāš^š )+ š/šš ćšššć^(āš) ((šš ā š)/āš)+ šŖ