The problem is to solve the equation $sin(5x^2) = cos(2x+6)$. The angle is in degrees.

AlgebraTrigonometryQuadratic EquationsEquation SolvingApproximation
2025/4/21

1. Problem Description

The problem is to solve the equation sin(5x2)=cos(2x+6)sin(5x^2) = cos(2x+6). The angle is in degrees.

2. Solution Steps

We know that sin(θ)=cos(90θ)sin(\theta) = cos(90 - \theta). Using this property, we can rewrite the given equation.
sin(5x2)=cos(2x+6)sin(5x^2) = cos(2x+6)
cos(905x2)=cos(2x+6)cos(90-5x^2) = cos(2x+6)
Since the cosine values are equal, we can equate the angles:
905x2=2x+690 - 5x^2 = 2x + 6
Rearranging the terms, we get a quadratic equation:
5x2+2x84=05x^2 + 2x - 84 = 0
We can solve this quadratic equation using the quadratic formula:
x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
where a=5a=5, b=2b=2, and c=84c=-84.
x=2±224(5)(84)2(5)x = \frac{-2 \pm \sqrt{2^2 - 4(5)(-84)}}{2(5)}
x=2±4+168010x = \frac{-2 \pm \sqrt{4 + 1680}}{10}
x=2±168410x = \frac{-2 \pm \sqrt{1684}}{10}
x=2±242110x = \frac{-2 \pm 2\sqrt{421}}{10}
x=1±4215x = \frac{-1 \pm \sqrt{421}}{5}
So the two possible solutions are:
x=1+4215x = \frac{-1 + \sqrt{421}}{5} and x=14215x = \frac{-1 - \sqrt{421}}{5}
Approximating 42120.518\sqrt{421} \approx 20.518
x1+20.518519.51853.9036x \approx \frac{-1 + 20.518}{5} \approx \frac{19.518}{5} \approx 3.9036
x120.518521.51854.3036x \approx \frac{-1 - 20.518}{5} \approx \frac{-21.518}{5} \approx -4.3036

3. Final Answer

The solutions are x=1+4215x = \frac{-1 + \sqrt{421}}{5} and x=14215x = \frac{-1 - \sqrt{421}}{5}.
x3.9036x \approx 3.9036 and x4.3036x \approx -4.3036.

Related problems in "Algebra"

The problem states that a sequence is defined by the formula $a_n = p + qn$. We are given that the s...

Linear EquationsSequencesArithmetic SequencesSystems of Equations
2025/6/24

The problem states that the twentieth term of the sequence $m, \frac{2}{3}m, \frac{1}{3}m, \dots$ is...

Arithmetic SequencesSequences and SeriesLinear Equations
2025/6/24

Find the number of natural numbers $a$ that satisfy the inequality $5 < \sqrt{a} < 6$.

InequalitiesSquare RootsNatural Numbers
2025/6/24

Simplify the expression $a^3 \times (-3a)^2$.

ExponentsSimplificationPolynomials
2025/6/24

The problem is to find the roots of the quadratic equation $x^2 + 9x + 14 = 0$.

Quadratic EquationsFactoringRoots
2025/6/23

The problem asks to find the solution set for the given quadratic equations by factorization. a) $x^...

Quadratic EquationsFactorizationSolution Sets
2025/6/23

We need to solve four inequalities for $x$. a) $3(2x - 1) < 2x + 5$ b) $-2(-2x + 4) \le x + 7$ c) $-...

InequalitiesLinear InequalitiesSolving Inequalities
2025/6/23

The problem is to solve the following inequalities: a) $4x + 8 \le 2x - 12$ b) $3x - 2 \ge x - 14$ c...

InequalitiesLinear InequalitiesSolving Inequalities
2025/6/23

We are asked to solve two inequalities for $x$. a) $x + 4 < 6$ b) $x - 2 \le -5$

InequalitiesLinear InequalitiesSolving Inequalities
2025/6/23

The problem requires solving two inequalities: a) $3(2x-1) < 2x + 5$ c) $-4(x-3) > -3(x-5)$

InequalitiesLinear InequalitiesAlgebraic Manipulation
2025/6/23