Q. Suppose that sinα=133 and 0∘<α<90∘Find the exact values of cos2α and tan2α.cos2α=tan2α=
Given Information: We are given that sin(α)=133 and α is in the first quadrant (0^\circ < \alpha < 90^\circ). To find cos(α/2) and tan(α/2), we can use the half-angle formulas for sine and cosine. The half-angle formula for cosine is:cos(α/2)=±(21+cos(α))Since α is in the first quadrant, cos(α) will be positive, and since we are looking for cos(α/2) in the first or second quadrant (because α/2 will be less than 90∘), we will choose the positive square root.First, we need to find cos(α) using the Pythagorean identity:cos2(α)+sin2(α)=1cos2(α)=1−sin2(α)cos2(α)=1−(133)2cos2(α)=1−139cos2(α)=1313−139cos2(α)=134α1α2
Find cos(α/2): Now we can find cos(α/2) using the half-angle formula:cos(α/2)=±(1+cos(α))/2cos(α/2)=(1+2/13)/2cos(α/2)=(13/13+2/13)/2cos(α/2)=(13+2)/213cos(α/2)=(13+2)/(213)cos(α/2)=(13+2)13/(21313)cos(α/2)=(13+2)13/(26)cos(α/2)=(13+213)/26cos(α/2)=(13+213)/26
Find tan(α/2): Next, we will find tan(α/2) using the half-angle formula for tangent, which is:tan(α/2)=±(1−cos(α))/(1+cos(α))Since α is in the first quadrant, tan(α) will be positive, and we will choose the positive square root for tan(α/2).tan(α/2)=(1−cos(α))/(1+cos(α))tan(α/2)=(1−2/13)/(1+2/13)tan(α/2)=(13/13−2/13)/(13/13+2/13)tan(α/2)=(13−2)/(13+2)tan(α/2)0tan(α/2)1tan(α/2)1