Using Formulaes
Last updated at July 28, 2026 by Teachoo
Transcript
Ex 7.1, 22 If š/šš„ f(x) = 4x3 ā 3/š„4 such that f(2) = 0, then f(x) is x4 + 1/š„3 ā 129/8 (B) x3 + 1/š„4 + 129/8 (C) x4 + 1/š„3 + 129/8 (D) x3 + 1/š„4 ā 129/8 Given š/šš„ f(x) = 4x3 ā 3/š„4 Integrating both sides ā«1āćš/šš„ š(š„) ć=ā«1ā(4š„^3ā 3/š„^4 )šš„ ā«1āš/šš„ š(š„)=4ā«1āćš„^3 šš„ćā3ā«1āć1/š„^4 šš„ć š(š„)=4ā«1āćš„^3 šš„ćā3ā«1āćš„^(ā4) šš„ć š(š„)=4 š„^(3 + 1)/(3 + 1)ā3 š„^(ā4 + 1)/(ā4 + 1)+š¶ š(š„)=4 š„^4/4 ā 3 š„^(ā3)/(ā3)+š¶ š(š„)=š„^4+š„^(ā3)+š¶ š(š„)=š„^4+ 1/š„^3 +š¶ Given š(2)=0 Putting š„=2 in (1) š(2)=(2)^4+ 1/(2)^3 +š¶ 0=16+ 1/8 +š¶ 0= (128 + 1)/8 +š¶ 0= 129/8 +š¶ š¶=(ā129)/8 Putting š¶=(ā129)/8 in (1) š(š„)=š„^4+ 1/š„^3 +š¶ ā š(š)=š^š+ š/š^š āššš/š ā“ Option (A) is correct.