Question

Find the Laplace transform of the function f (t) = 3t^4 – 2t^3 + 4e^-3t – 2sin5t + 3cos2t. (a) 72/s^5 – 12/s^4 + 4/(s+3)+10/(s^2+25)+3s/(s^2+4) (b) 72/s^5 – 12/s^4 + 4/(s+3)-10/(s^2+25)+3s/(s^2+4) (c) 72/s^5 – 12/s^4 – 4/(s+3)+10/(s^2+25)+3s/(s^2+4) (d) 72/s^5 – 12/s^4 – 4/(s+3)-10/(s^2+25)+3s/(s^2+4) I had been asked this question during an online exam. My doubt stems from Operational Transforms topic in portion Intoduction to the Laplace Transform of Network Theory Select the correct answer from above options network theory questions and answers, network theory questions pdf, network theory question bank, network theory gate questions and answers pdf, mcq on network theory pdf, gate network theory questions and solutions, network theory mcq Test , ies network theory questions, Network theory Questions for GATE EC Exam, Network Theory MCQ (Multiple Choice Questions)

Answer 1

Right answer is (b) 72/s^5 – 12/s^4 + 4/(s+3)-10/(s^2+25)+3s/(s^2+4) Best explanation: L (3t^4 -2t^3+4e^-3t – 2sin5t +3cos2t) = 3 L (t^4)-2L (t^3)+4L (e^-3t)-2L (sin5t) + 3L (cos2t) = 72/s^5) -12/s^4 +4/(s+3)-10/(s^2+25)+3s/(s^2+4).