MathematicsMedium202×since 2002Q5829Let a^\hat{a}a^ and b^\hat{b}b^ be two unit vectors such that the angle between them is π4\frac{\pi}{4}4π. If θ\thetaθ is the angle between the vectors (a^+b^)(\hat{a}+\hat{b})(a^+b^) and (a^+2b^+2(a^×b^))(\hat{a}+2 \hat{b}+2(\hat{a} \times \hat{b}))(a^+2b^+2(a^×b^)), then the value of 164 cos2θ164 \,\cos ^{2} \theta164cos2θ is equal to :A90+27290+27 \sqrt{2}90+272B45+18245+18 \sqrt{2}45+182C90+3290+3 \sqrt{2}90+32D54+90254+90 \sqrt{2}54+902Check answerSkip