Question
Solve the equation
Solve for a
a∈/R
Alternative Form
No real solution
Evaluate
cot(a)−21−sec2(a)=1cot(a)+tan(a)
Divide the terms
cot(a)−21−sec2(a)=cot(a)+tan(a)
Cancel equal terms on both sides of the expression
−21−sec2(a)=tan(a)
Use sec2(x)=tan2(x)+1 to rewrite the expression
−23−tan2(a)=tan(a)
Move the expression to the left side
−23−tan2(a)−tan(a)=0
Rewrite in standard form
−tan2(a)−tan(a)−23=0
Multiply both sides
tan2(a)+tan(a)+23=0
Multiply both sides
2(tan2(a)+tan(a)+23)=2×0
Calculate
2tan2(a)+2tan(a)+3=0
Substitute a=2,b=2 and c=3 into the quadratic formula tan(a)=2a−b±b2−4ac
tan(a)=2×2−2±22−4×2×3
Simplify the expression
tan(a)=4−2±22−4×2×3
Simplify the expression
More Steps

Evaluate
22−4×2×3
Multiply the terms
More Steps

Multiply the terms
4×2×3
Multiply the terms
8×3
Multiply the numbers
24
22−24
Evaluate the power
4−24
Subtract the numbers
−20
tan(a)=4−2±−20
Simplify the radical expression
More Steps

Evaluate
−20
Evaluate the power
20×−1
Evaluate the power
20×i
Evaluate the power
More Steps

Evaluate
20
Write the expression as a product where the root of one of the factors can be evaluated
4×5
Write the number in exponential form with the base of 2
22×5
The root of a product is equal to the product of the roots of each factor
22×5
Reduce the index of the radical and exponent with 2
25
25×i
tan(a)=4−2±25×i
Separate the equation into 2 possible cases
tan(a)=4−2+25×itan(a)=4−2−25×i
Simplify the expression
More Steps

Evaluate
tan(a)=4−2+25×i
Divide the terms
More Steps

Evaluate
4−2+25×i
Rewrite the expression
42(−1+5×i)
Cancel out the common factor 2
2−1+5×i
Use b−a=−ba=−ba to rewrite the fraction
−21−5×i
Simplify
−21+25i
tan(a)=−21+25i
tan(a)=−21+25itan(a)=4−2−25×i
Simplify the expression
More Steps

Evaluate
tan(a)=4−2−25×i
Divide the terms
More Steps

Evaluate
4−2−25×i
Rewrite the expression
42(−1−5×i)
Cancel out the common factor 2
2−1−5×i
Use b−a=−ba=−ba to rewrite the fraction
−21+5×i
Simplify
−21−25i
tan(a)=−21−25i
tan(a)=−21+25itan(a)=−21−25i
Rearrange the terms
a∈/Ra∈/R
Solution
a∈/R
Alternative Form
No real solution
Show Solution