Man pages matching name qwtscalearithmetic in section 3:

QwtScaleArithmetic.3.en	debian 10 / libqwt-doc
QwtScaleArithmetic.3.en	debian 10 / libqwt5-doc
QwtScaleArithmetic.3.en	debian 11 / libqwt-doc
QwtScaleArithmetic.3.en	debian 12 / libqwt-doc