Question and Answers Forum

All Questions      Topic List

Differentiation Questions

Previous in All Question      Next in All Question      

Previous in Differentiation      Next in Differentiation      

Question Number 12704 by @ANTARES_VY last updated on 29/Apr/17

y=sin2x−x  (x∈[0;𝛑])  find  the  range  of  the  function.

y=sin2xx(x[0;π])findtherangeofthefunction.

Answered by mrW1 last updated on 29/Apr/17

y=sin 2x−x  y′=2cos 2x−1    for y to be local max. or min.:  y′=0⇒2cos 2x−1=0⇒cos 2x=(1/2)  ⇒2x=(π/3),((5π)/3)  ⇒x=(π/6),((5π)/6)    at x=π:  y=sin (2π)−π=−π  at x=((5π)/6):  y=sin (((5π)/3))−((5π)/6)=−((√3)/2)−((5π)/6)=−((3(√3)+5π)/6)<−π    at x=0:  y=sin (0)+0=0  at x=(π/6):  y=sin ((π/3))−(π/6)=((√3)/2)−(π/6)=((3(√3)−π)/6)>0    for x∈[0,π]  y∈[−((3(√3)+5π)/6),((3(√3)−π)/6)]

y=sin2xxy=2cos2x1forytobelocalmax.ormin.:y=02cos2x1=0cos2x=122x=π3,5π3x=π6,5π6atx=π:y=sin(2π)π=πatx=5π6:y=sin(5π3)5π6=325π6=33+5π6<πatx=0:y=sin(0)+0=0atx=π6:y=sin(π3)π6=32π6=33π6>0forx[0,π]y[33+5π6,33π6]

Terms of Service

Privacy Policy

Contact: info@tinkutara.com