Q. Solve the given equation secx−1tanx+1−cosxsinx=2cosecx
Simplify left-hand side: We will start by simplifying the left-hand side of the equation. The first term (tanx)/(secx−1) can be rewritten using the identity tanx=sinx/cosx and secx=1/cosx. This gives us (sinx/cosx)/(1/cosx−1).
Combine terms: Simplify the expression further by multiplying the numerator and denominator by cosx to get rid of the fraction in the denominator. This results in cosxsinx⋅1−cosxcosx, which simplifies to 1−cosxsinx.
Simplify right-hand side: Now, let's look at the second term (sinx)/(1−cosx). We notice that it is identical to the simplified form of the first term. Therefore, we can combine them to get 2×(sinx/(1−cosx)).
Verify identity: Next, we will simplify the right-hand side of the equation. The identity cosecx=sinx1 allows us to rewrite 2cosecx as sinx2.
Rewrite expressions: Now we have 2×(1−cosxsinx) on the left-hand side and sinx2 on the right-hand side. To verify the identity, we need to show that these two expressions are equal.
Common denominator: We can rewrite the left-hand side as 1−cosx2sinx and the right-hand side as sin2x2sinx. To compare these two expressions, we need to have a common denominator.
Apply identity: We know that sin2x+cos2x=1, which means sin2x=1−cos2x. We can use this identity to rewrite the denominator of the right-hand side expression as 1−cos2x.
Simplify further: Now the right-hand side becomes 1−cos2x2sinx. Since 1−cos2x is the same as sin2x, we can simplify this to sin2x2sinx, which simplifies further to sinx2.
Confirm equality: We see that both sides of the equation have the same expression sinx2, which means the identity secx−1tanx+1−cosxsinx=2cscx holds true.
More problems from Sum of finite series starts from 1