Q. Write the given expression as an algebraic expression in x.tan(2cos−1(x))
Use Double-Angle Formula: We need to express tan(2cos−1(x)) as an algebraic expression in x. To do this, we will use the double-angle formula for tangent and the trigonometric identity that relates the cosine of an angle to the tangent of half that angle.
Find Tangent of θ: The double-angle formula for tangent is tan(2θ)=1−tan2(θ)2tan(θ). We will let θ=cos−1(x), so we need to find an expression for tan(cos−1(x)).
Apply Pythagorean Theorem: To find tan(cos−1(x)), we consider a right triangle where the angle θ has a cosine of x. By definition of cosine, cos(θ)=hypotenuseadjacent. If we let the adjacent side be x and the hypotenuse be 1, then we need to find the opposite side using the Pythagorean theorem.
Calculate Opposite Side: The Pythagorean theorem states that in a right triangle with sides a, b, and hypotenuse c, a2+b2=c2. Here, we have the adjacent side a=x and hypotenuse c=1, so we need to solve for the opposite side b: b2=c2−a2=12−x2=1−x2.
Determine Tangent of θ: Taking the square root of both sides to find b, we get b=1−x2. We must be careful to consider only the positive square root since we are dealing with lengths in a triangle.
Substitute into Formula: Now we have the opposite side b=1−x2 and the adjacent side a=x. The tangent of θ is tan(θ)=adjacentopposite=x1−x2.
Square Tangent of θ: Substituting tan(θ) into the double-angle formula, we get tan(2θ)=1−tan2(θ)2tan(θ)=1−(1−x2/x)22(1−x2/x).
Simplify Expression: Simplify the expression by squaring tan(θ): (x1−x2)2=x21−x2.
Combine Denominator Terms: Substitute this back into the double-angle formula: tan(2θ)=x2(1−x2)/(1−x21−x2).
Final Simplification: Combine the terms in the denominator: 1−x21−x2=x2x2−(1−x2)=x2x2−1+x2=x22x2−1.
Final Simplification: Combine the terms in the denominator: 1−x21−x2=x2x2−(1−x2)=x2x2−1+x2=x22x2−1.Now we have tan(2θ)=(2x2−1)/x22(1−x2/x). To simplify, multiply both the numerator and the denominator by x2.
Final Simplification: Combine the terms in the denominator: 1−x21−x2=x2x2−(1−x2)=x2x2−1+x2=x22x2−1.Now we have tan(2θ)=(2x2−1)/x22(1−x2)/x. To simplify, multiply both the numerator and the denominator by x2.After multiplying, we get tan(2θ)=2x2−12x1−x2.
Final Simplification: Combine the terms in the denominator: 1−x21−x2=x2x2−(1−x2)=x2x2−1+x2=x22x2−1. Now we have tan(2θ)=(2x2−1)/x22(1−x2)/x. To simplify, multiply both the numerator and the denominator by x2. After multiplying, we get tan(2θ)=2x2−12x1−x2. This is the simplified algebraic expression for tan(2cos−1(x)): tan(2cos−1(x))=2x2−12x1−x2.
More problems from Evaluate integers raised to rational exponents