Tìm nghiệm chung của phương trình sin2x + cosx = 0 và sinx = 0 trong khoảng [0, 2π].

a) sin 2x + cos x = 0 asin x cos x + COST = cosx (asinx+1)=0. = L cos X=0 sinx = -|. X=90,270°. Q3/4 x=90% - 90⋅. 2 b) sin 2x - cos 2x = 0 sinax = losax. 2cosx = sin2x. 0 ≤ x ≤ 3π sin2x = 2sinxcosx 2cosx = 2sinxcosx. 0 = 2sinxcosx − 2cosx 2cosx(1 − sinx) = 0 cosx = 0 sinx = 1 x = π. 2 x = 3π. 2 x = 5π. 2 sin2x. (x2 − 3x + 3) ≥ 0, x + 2 x + 3. > 2x + 3 x + 6 . 2. Draw a graph of the ... sin 2x = sinx, 2 sinx + cosx = 1, log(x2 + 1) = 2 log(3 − x). 4. Express ... cos(-x) = cos(x) sin(-x) = -sin(x) tan(-x) = -tan(x). Double angle formulas sin(2x) = 2 sinxcosx cos(2x) = (cosx). 2 - (sinx)2 cos(2x) = 2(cosx). 2 - 1 cos(2x)= ... May 15, 2017 ... Solve: sin 2x - cos x = 0. 31K views · 7 years ago ...more. Anna Herbert. 76. Subscribe. 222. Share. Save. Report. Comments. The solutions for sin(2x) + cos(x) = 0 between 0 and 2π are . To solve this equation, we will start by using the double angle identity for sine. Apr 13, 2017 ... 2sinxcosx + 2cosx = 0 divide through by 2 sinxcosx + cosx = 0 factor cosx (sinx + 1) = 0 So either cosx = 0 and this happens at pi/2 + pi*n where Apr 5, 2018 ... Explanation: ... either factor should be zero. ... x=3π2+2kπ . b. 2sin x + 1 = 0 --> sin ... Mar 18, 2014 ... Solve sin(2x)+sinx=0. 78K views · 11 years ago ...more. Mark Dwyer ... General Solution for sinx =0 cosx = 0 and tan x = 0 Primary Trig Ratio. 11) 5 sin 4x = 2 sin 2x. 12) 2 sin2x − cos 2x − cos x = 0. Use Identity (2 cos 2x – 1) + cos x = 0. Factorise (2cos x-1)(cos x+1) = 0. Solve cos x = -1, ½.