Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

Find all angles, 
0^(@) <= theta < 360^(@), that satisfy the equation below, to the nearest tenth of a degree.

8sin^(2)theta-11 sin theta-6=-9sin theta-3
Answer: 
theta=

Find all angles, 0^{\circ} \leq \theta<360^{\circ} , that satisfy the equation below, to the nearest tenth of a degree.\newline8sin2θ11sinθ6=9sinθ3 8 \sin ^{2} \theta-11 \sin \theta-6=-9 \sin \theta-3 \newlineAnswer: θ= \theta=

Full solution

Q. Find all angles, 0θ<360 0^{\circ} \leq \theta<360^{\circ} , that satisfy the equation below, to the nearest tenth of a degree.\newline8sin2θ11sinθ6=9sinθ3 8 \sin ^{2} \theta-11 \sin \theta-6=-9 \sin \theta-3 \newlineAnswer: θ= \theta=
  1. Simplify the equation: First, we need to simplify the given equation by moving all terms to one side to set the equation to zero.\newline8sin2θ11sinθ6=9sinθ38\sin^{2}\theta - 11\sin \theta - 6 = -9\sin \theta - 3\newlineAdding 9sinθ9\sin \theta and 33 to both sides, we get:\newline8sin2θ11sinθ+9sinθ6+3=08\sin^{2}\theta - 11\sin \theta + 9\sin \theta - 6 + 3 = 0\newline8sin2θ2sinθ3=08\sin^{2}\theta - 2\sin \theta - 3 = 0
  2. Factor the quadratic equation: Next, we factor the quadratic equation in terms of sinθ\sin \theta. We look for two numbers that multiply to (8)(3)=24(8)(-3) = -24 and add up to 2-2. The numbers 6-6 and +4+4 satisfy these conditions. So we can write the equation as: (8sin2θ+4sinθ)(6sinθ+3)=0(8\sin^{2}\theta + 4\sin \theta) - (6\sin \theta + 3) = 0
  3. Factor by grouping: Now, we factor by grouping.\newlineFirst group: 8sin2θ+4sinθ=4sinθ(2sinθ+1)8\sin^{2}\theta + 4\sin \theta = 4\sin \theta(2\sin \theta + 1)\newlineSecond group: 6sinθ3=3(2sinθ+1)-6\sin \theta - 3 = -3(2\sin \theta + 1)\newlineThe equation becomes:\newline4sinθ(2sinθ+1)3(2sinθ+1)=04\sin \theta(2\sin \theta + 1) - 3(2\sin \theta + 1) = 0
  4. Factor out common factor: We can now factor out the common factor (2sinθ+1)(2\sin \theta + 1):(2sinθ+1)(4sinθ3)=0(2\sin \theta + 1)(4\sin \theta - 3) = 0
  5. Set factors equal to zero: We set each factor equal to zero and solve for sinθ\sin \theta:2sinθ+1=02\sin \theta + 1 = 0 or 4sinθ3=04\sin \theta - 3 = 0 For the first equation: 2sinθ=12\sin \theta = -1 => sinθ=12\sin \theta = -\frac{1}{2} For the second equation: 4sinθ=34\sin \theta = 3 => sinθ=34\sin \theta = \frac{3}{4}
  6. Find angles for sinθ=12\sin \theta = -\frac{1}{2}: We find the angles for sinθ=12\sin \theta = -\frac{1}{2}. Since the sine function is negative in the third and fourth quadrants, we look for angles in those quadrants. The reference angle whose sine is 12\frac{1}{2} is 3030 degrees. Therefore, the angles are 180+30=210180 + 30 = 210 degrees and 36030=330360 - 30 = 330 degrees.
  7. Find angles for sinθ=34\sin \theta = \frac{3}{4}: We find the angles for sinθ=34\sin \theta = \frac{3}{4}. This is not a standard value for the sine function, so we will use a calculator to find the angle. Using the inverse sine function, we find: θ=sin1(34)\theta = \sin^{-1}(\frac{3}{4}) θ48.6\theta \approx 48.6 degrees (to the nearest tenth) Since the sine function is positive in the first and second quadrants, the other angle is 18048.6=131.4180 - 48.6 = 131.4 degrees.
  8. Final angles: We now have all the angles that satisfy the equation: θ48.6\theta \approx 48.6 degrees, 131.4131.4 degrees, 210210 degrees, and 330330 degrees.

More problems from Csc, sec, and cot of special angles