What is the general solution for tan^2(x)+7tan(x)+9=0 ?

The general solution for tan^2(x)+7tan(x)+9=0 is x=-1.03835…+pin,x=-1.38440…+pin

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tan^2(x)+7tan(x)+9=0

tan^{2} (x) + 7 tan (x) + 9 = 0

x = - 1.03835 \dots + πn, x = - 1.38440 \dots + πn

Degrees

x = - 59.49352 \dots^{\circ} + 18 0^{\circ} n, x = - 79.32055 \dots^{\circ} + 18 0^{\circ} n

Solution steps

tan^{2} (x) + 7 tan (x) + 9 = 0

Solve by substitution

tan^{2} (x) + 7 tan (x) + 9 = 0

Let:

tan (x) = u

u^{2} + 7 u + 9 = 0

u^{2} + 7 u + 9 = 0 : u = \frac{- 7 + 13}{2}, u = \frac{- 7 - 13}{2}

u^{2} + 7 u + 9 = 0

Solve with the quadratic formula

u^{2} + 7 u + 9 = 0

Quadratic Equation Formula:

For

a = 1, b = 7, c = 9

u_{1, 2} = \frac{- 7 \pm 7 ^{2} - 4 \cdot 1 \cdot 9}{2 \cdot 1}

u_{1, 2} = \frac{- 7 \pm 7 ^{2} - 4 \cdot 1 \cdot 9}{2 \cdot 1}

7^{2} - 4 \cdot 1 \cdot 9 = 13

7^{2} - 4 \cdot 1 \cdot 9

Multiply the numbers:

4 \cdot 1 \cdot 9 = 36

= 7^{2} - 36

7^{2} = 49

= 49 - 36

Subtract the numbers:

49 - 36 = 13

= 13

u_{1, 2} = \frac{- 7 \pm 13}{2 \cdot 1}

Separate the solutions

u_{1} = \frac{- 7 + 13}{2 \cdot 1}, u_{2} = \frac{- 7 - 13}{2 \cdot 1}

u = \frac{- 7 + 13}{2 \cdot 1} : \frac{- 7 + 13}{2}

\frac{- 7 + 13}{2 \cdot 1}

Multiply the numbers:

2 \cdot 1 = 2

= \frac{- 7 + 13}{2}

u = \frac{- 7 - 13}{2 \cdot 1} : \frac{- 7 - 13}{2}

\frac{- 7 - 13}{2 \cdot 1}

Multiply the numbers:

2 \cdot 1 = 2

= \frac{- 7 - 13}{2}

The solutions to the quadratic equation are:

u = \frac{- 7 + 13}{2}, u = \frac{- 7 - 13}{2}

Substitute back

u = tan (x)

tan (x) = \frac{- 7 + 13}{2}, tan (x) = \frac{- 7 - 13}{2}

tan (x) = \frac{- 7 + 13}{2}, tan (x) = \frac{- 7 - 13}{2}

tan (x) = \frac{- 7 + 13}{2} : x = arctan (\frac{- 7 + 13}{2}) + πn

tan (x) = \frac{- 7 + 13}{2}

Apply trig inverse properties

tan (x) = \frac{- 7 + 13}{2}

General solutions for

tan (x) = \frac{- 7 + 13}{2}

tan (x) = - a \Rightarrow x = arctan (- a) + πn

x = arctan (\frac{- 7 + 13}{2}) + πn

x = arctan (\frac{- 7 + 13}{2}) + πn

tan (x) = \frac{- 7 - 13}{2} : x = arctan (\frac{- 7 - 13}{2}) + πn

tan (x) = \frac{- 7 - 13}{2}

Apply trig inverse properties

tan (x) = \frac{- 7 - 13}{2}

General solutions for

tan (x) = \frac{- 7 - 13}{2}

tan (x) = - a \Rightarrow x = arctan (- a) + πn

x = arctan (\frac{- 7 - 13}{2}) + πn

x = arctan (\frac{- 7 - 13}{2}) + πn

Combine all the solutions

x = arctan (\frac{- 7 + 13}{2}) + πn, x = arctan (\frac{- 7 - 13}{2}) + πn

Show solutions in decimal form

x = - 1.03835 \dots + πn, x = - 1.38440 \dots + πn

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What is the general solution for tan^2(x)+7tan(x)+9=0 ?
The general solution for tan^2(x)+7tan(x)+9=0 is x=-1.03835…+pin,x=-1.38440…+pin