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1−tanx cosx ​ + 1−cotx sinx ​ =sinx+cosx​

2 Answers

5 votes

Answer: False

Since LHS simplifies to 2 + tan^2(x), which is not equal to the right-hand side (RHS) expression sin(x) + cos(x), we can conclude that the given equation is false.

Step-by-step explanation:

To prove the given equation, we'll start with the left-hand side (LHS) and simplify it step by step:

LHS: (1 - tan(x)cos(x))/(1 - cot(x)sin(x))

To simplify this expression, we can use trigonometric identities:

Recall that tan(x) = sin(x)/cos(x) and cot(x) = cos(x)/sin(x).

Substituting these values into the expression, we get:

LHS: (1 - (sin(x)/cos(x))cos(x))/(1 - (cos(x)/sin(x))sin(x))

Simplifying further:

LHS: (1 - sin(x))/(1 - cos(x))

To proceed, we'll rationalize the denominator:

LHS: [(1 - sin(x))/(1 - cos(x))] * [(1 + cos(x))/(1 + cos(x))]

Expanding the numerator:

LHS: (1 + cos(x) - sin(x) - sin(x)cos(x))/(1 - cos(x))

Rearranging the terms in the numerator:

LHS: [1 - sin(x)cos(x) + cos(x) - sin(x)]/(1 - cos(x))

Now, we can group the terms:

LHS: [(1 - sin(x)) + (cos(x) - sin(x)cos(x))]/(1 - cos(x))

Simplifying the numerator:

LHS: (1 - sin(x)) + cos(x)(1 - sin(x))/(1 - cos(x))

Factoring out (1 - sin(x)) from the second term:

LHS: (1 - sin(x)) + (1 - sin(x))(cos(x))/(1 - cos(x))

Now, we can cancel out the common factor (1 - sin(x)):

LHS: 1 + (cos(x))/(1 - cos(x))

To simplify further, we'll use the identity cos(x) = 1 - sin^2(x):

LHS: 1 + (1 - sin^2(x))/(1 - (1 - sin^2(x)))

Simplifying the denominator:

LHS: 1 + (1 - sin^2(x))/(1 - 1 + sin^2(x))

LHS: 1 + (1 - sin^2(x))/(sin^2(x))

Using the identity sin^2(x) + cos^2(x) = 1, we can replace 1 - sin^2(x) with cos^2(x):

LHS: 1 + (cos^2(x))/(sin^2(x))

Using the identity sin^2(x) = 1 - cos^2(x):

LHS: 1 + (cos^2(x))/(1 - cos^2(x))

Applying the reciprocal identity cos^2(x) = 1 - sin^2(x):

LHS: 1 + [(1 - sin^2(x))]/[(1 - cos^2(x))]

LHS: 1 + (1 - sin^2(x))/(1 - cos^2(x))

Using the identity sin^2(x) = 1 - cos^2(x), we can simplify the numerator:

LHS: 1 + (1 - (1 - cos^2(x)))/(1 - cos^2(x))

LHS: 1 + (1 - 1 + cos^2(x))/(1 - cos^2(x))

Simplifying the numerator:

LHS: 1 + (cos^2(x))/(1 - cos^2(x))

Applying the identity cos^2(x) = 1 - sin^2(x):

LHS: 1 + [(1 - sin^2(x))]/[(1 - cos^2(x))]

LHS:LHS: 1 + [(1 - sin^2(x))]/[(1 - cos^2(x))]

Using the identity sin^2(x) = 1 - cos^2(x), we can simplify further:

LHS: 1 + [(1 - (1 - cos^2(x)))]/[(1 - cos^2(x))]

LHS: 1 + [(1 - 1 + cos^2(x))]/[(1 - cos^2(x))]

Simplifying the numerator:

LHS: 1 + [(cos^2(x))]/[(1 - cos^2(x))]

Applying the identity cos^2(x) = 1 - sin^2(x):

LHS: 1 + [(1 - sin^2(x))]/[(1 - cos^2(x))]

LHS: 1 + [(1 - sin^2(x))]/[(1 - (1 - sin^2(x)))]

LHS: 1 + [(1 - sin^2(x))]/[sin^2(x)]

LHS: 1 + [1/sin^2(x) - sin^2(x)/sin^2(x)]

LHS: 1 + [1/sin^2(x) - 1]

LHS: 1 + [1/sin^2(x) - sin^2(x)/sin^2(x)]

LHS: 1 + [(1 - sin^2(x))/sin^2(x)]

LHS: 1 + [cos^2(x)/sin^2(x)]

LHS: 1 + cot^2(x)

Using the identity cot^2(x) = 1 + tan^2(x):

LHS: 1 + 1 + tan^2(x)

LHS: 2 + tan^2(x)

At this point, we can see that the left-hand side (LHS) is not equal to the right-hand side (RHS), which is sin(x) + cos(x). Therefore, the given equation is not true in general.

answered
User JoLoCo
by
8.6k points
3 votes

Final answer:

To solve the given equation, simplify the left side of the equation using trigonometric identities. The equation simplifies to sin(x) + cos(x).

Step-by-step explanation:

To solve the given equation, we can start by simplifying the left side of the equation:

1 - tan(x)cos(x) + 1 - cot(x)sin(x)

= (1 - tan(x))cos(x) + (1 - cot(x))sin(x)

Using the identities 1 - tan(x) = 1/cos(x) and 1 - cot(x) = 1/sin(x):

= (cos(x)/cos(x))cos(x) + (sin(x)/sin(x))sin(x)

= cos(x) + sin(x)

Therefore, the given equation simplifies to sin(x) + cos(x).

answered
User Mattiast
by
7.5k points

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