Using the Sum to Product Formula for Trig, Calculate Cos(45°) + Cos(30°)

Cos(u) + Cos(v) = 2cos(a)cos(b)

a and b are defined below:

a = | u + v |

2 |

a = | 45 + 30 |

2 |

a = | 75 |

2 |

a = 37.5

b = | u - v |

2 |

b = | 45 - 30 |

2 |

b = | 15 |

2 |

b = 7.5

With a = 37.5° and b = 7.5°, we have

cos(45) + sin(30) = 2cos(37.5)cos(7.5)

cos(45) + sin(30) = 2(1)(1)

cos(45 + 30) =